High speed logic and memory family using ring segment buffer

• US 5,030,853 A
• Filed: 03/21/1990
• Issued: 07/09/1991
• Est. Priority Date: 03/21/1990
• Status: Expired due to Term

• Current Assignee: Technology Properties Limited LLC
• Original Assignee: Thunderbird Technologies Incorporated
• Inventors: Vinal, Albert W.
• Primary Examiner(s): Miller, Stanley D.
• Assistant Examiner(s): Bertelson, David R.
• Application Number:
  US07/497,103
• Time in Patent Office: 475 Days
• Field of Search: 307/443, 307/446, 307/448, 307/450, 307/451, 307/475, 307/570, 307/571, 307/585, 307/576, 307/579, 307/542, 307/544, 307/300, 307/280, 307/255, 377/122, 377/124
• US Class Current: 326/84
• CPC Class Codes: H01L 27/0716 in combination with vertical bipolar transistors and diodes, or capacitors, or resistors
• CPC Class Codes: H01L 27/11898 Input and output buffer/driver structures
• CPC Class Codes: H03K 17/567 Circuits characterised by the use of more than one type of semiconductor device, e.g. BIMOS, composite devices such as IGBT
• CPC Class Codes: H03K 19/01707 in asynchronous circuits
• CPC Class Codes: H03K 19/09448 in combination with bipolar transistors [BIMOS]
• CPC Class Codes: H03K 19/0948 using CMOS or complementary insulated gate field-effect transistors
• CPC Class Codes: H03K 3/03 Astable circuits
• CPC Class Codes: H03K 3/356156 with synchronous operation

Abstract

A logic and memory family using CMOS technology operates at high speeds using a Ring Segment Buffer to couple logic gates to one another in an integrated circuit chip, and to couple memory cells to other circuits to provide shift registers, triggers, clock pulse generators and other memory related circuits. The Ring Segment Buffer comprises one or more serially connected complementary field effect transistor (FET) inverter stages, with the output of a preceding stage being connected to the input of a succeeding stage. The N-channel FET in each inverter stage has a channel width which is less than a predetermined factor (K) times the width of the N-channel of the immediately preceding stage. By maintaining the K channel width relationship, the Ring Segment Buffer can drive large capacitive loads at high speed. The Ring Segment Buffer may also provide a predetermined delay which is a function of channel length and the number of stages. For large capacitive loads, the last stage of the Ring Segment Buffer may be replaced by a bipolar transistor-FET driver in which minority carrier lifetime controlled bipolar transistors are used.

The Buffer Cell Logic and Delay Storage technology of the present invention may operate at speeds of 300 megahertz or more using conventional semiconductor fabrication processes in which conventional CMOS logic and memory technology operates at 70 megahertz or less. A fourfold speed improvement is thereby obtained.

Claims

1. An integrated circuit Ring Segment Buffer for driving a capacitive load, comprising:

a plurality of serially connected complementary field effect transistor inverter stages, each of said complementary field effect transistor inverter stages comprising a serially connected N-channel field effect transistor and P-channel field effect transistor, the N-channel and P-channel field effect transistors having predetermined channel widths and channel lengths, each of said complementary field effect transistor inverter stages having an input and an output, with the output of an immediately preceding inverter stage being connected to the input of an immediately succeeding inverter stage, and the output of the last inverter stage being connected to the capacitive load;

the N-channel field effect transistor in each inverter stage having a channel width which is less than a predetermined factor times the width of the N-channel of the immediately preceding inverter stage, whereby said Ring Segment Buffer drives said capacitive load at high speed.

2. The Ring Segment Buffer of claim 1 wherein the input of the first inverter stage is connected to the output of a logic gate, whereby the logic gate drives the capacitive load at high speed.

3. The Ring Segment Buffer of claim 2 wherein said logic gate includes at least one N-channel field effect transistor, and wherein the N-channel field effect transistor in the first inverter stage has a channel width which is less than said predetermined factor times the width of the at least one N-channel field effect transistor in the logic gate.

4. The Ring Segment Buffer of claim 1 wherein the input of the first stage is connected to a memory cell, whereby the memory cell drives the capacitive load at high speed.

5. The Ring Segment Buffer of claim 2 wherein said memory cell includes at least one N-channel field effect transistor, and wherein the N-channel field effect transistor in the first inverter stage has a channel width which is less than said predetermined factor times the width of the N-channel field effect transistor in the memory cell.

6. The Ring Segment Buffer of claim 1 wherein the plurality of serially connected complementary field effect transistor inverter stages comprise an odd number of serially connected complementary field effect transistor stages, whereby the output of the last inverter stage inverts the signal at the input of the first inverter stage.

7. The Ring Segment Buffer of claim 1 wherein the plurality of serially connected complementary field effect transistor inverter stages comprise an even number of serially connected complementary field effect transistor stages, whereby the output of the last inverter stage does not invert the signal at the input of the first inverter stage.

8. The Ring Segment Buffer of claim 2 wherein the plurality of serially connected complementary field effect transistor inverter stages comprise an odd number of serially connected complementary field effect transistor stages, whereby the Ring Segment Buffer drives the capacitive load with an inverted logic signal from said logic gate.

9. The Ring Segment Buffer of claim 2 wherein the plurality of serially connected complementary field effect transistor inverter stages comprise an even number of serially connected complementary field effect transistor stages, whereby the Ring Segment Buffer drives the capacitive load with an non-inverted logic signal from said logic gate.

10. The Ring Segment Buffer of claim 1 wherein the P-channel field effect transistor of each of the inverter stages has a channel which is wider than the channel of the corresponding N-channel field effect transistor of each inverter stage by a second predetermined factor.

11. The Ring Segment Buffer of claim 10 wherein said second predetermined factor comprises η

, the ratio of electron mobility in N-channel field effect transistor to hole mobility in the P-channel field effect transistors.

12. The Ring Segment Buffer of claim 1 wherein said predetermined factor is equal to ##EQU43## where I_sat * is the channel saturation current of a square channel field effect transistor having width and length of L_o ;

T_rise is the desired rise time of the Ring Segment Buffer;

η

is the ratio of electron mobility in the N-channel to hole mobility in the P-channel;

Cg* is the effective gate capacity per unit area of the capacitive load;

L_o is the channel length for the complementary field effect transistors in the inverter stages;

V_dd is the power supply voltage applied to the Ring Segment Buffer;

L_c is the interconnecting conductor length between inverter stages; and

α

_o is equal to Cg*(1+η

)/C_i β

, where C_i is equal to the field oxide insulator capacity per unit area, and β

is equal to the ratio of the width of the interconnecting conductor at the output of the inverter and the width of the first N-channel in the Ring Segment Buffer.

13. The Ring Segment Buffer of claim 1 wherein the last inverter stage comprises an integrated complementary bipolar transistor and field effect transistor inverter, with the N-channel field effect transistor in the last stage having a gate width which is reduced from the predetermined factor times the gate width of the N-channel of the immediately proceeding stage by a second predetermined factor.

14. The Ring Segment Buffer of claim 13 wherein the integrated bipolar transistor comprises a Lifetime Controlled bipolar transistor.

15. The Ring Segment Buffer of claim 14 wherein said second predetermined factor is about β

/3.25, where β

is the current gain of the Lifetime Controlled bipolar transistor.

16. The Ring Segment Buffer of claim 14 wherein the minority carrier lifetime in said Lifetime Controlled bipolar transistor is less than 8e-9 seconds.

17. The Ring Segment Buffer of claim 16 wherein the minority carrier lifetime is less than ten times the desired high speed rise time.

18. The Ring Segment Buffer of claim 16 wherein the Lifetime Controlled bipolar transistor has a current gain of at least twenty.

19. The Ring Segment Buffer of claim 14 wherein the base region of the Lifetime Controlled bipolar transistor is doped with gold.

20. The Ring Segment Buffer of claim 19 wherein the gold doping density is at least 10e15 cm-3.

21. The Ring Segment Buffer of claim 1 wherein the channel lengths of the complementary field effect transistors in the plurality of serially connected complementary field effect transistor inverter stages is at least a first predetermined length, to thereby provide a predetermined delay from the input of the first inverter stage to the output of the last inverter stage.

22. The Ring Segment Buffer of claim 10 wherein the channel lengths L_o of the complementary field effect transistors in the plurality of serially connected complementary field effect transistor inverters stages are selected to provide a desired delay time T_d according to the following relationship:

space="preserve" listing-type="equation">T.sub.d =0.65 NT.sub.rise

23. An integrated circuit Buffer Cell Logic chip comprising:

a plurality of interconnected logic gates, each having a predetermined number of logic gate inputs and a logic gate output, the logic gate output of each logic gate driving an associated effective capacitance, for performing a predetermined logic function;

a plurality of buffers, each having an input and an output, a respective one of said plurality of buffers being associated with a respective one of said plurality of logic gates, the input of each buffer being connected to the logic output of the associated logic gate, the output of each buffer being connected to the associated effective capacitance;

each of said buffers being configured to drive the associated effective capacitance at a predetermined Buffer Cell Logic chip speed;

whereby each of the logic gates in said integrated circuit logic chip performs said predetermined logic function at said predetermined Buffer Cell Logic chip speed, notwithstanding the associated effective capacitance for each logic gate.

24. The integrated circuit Buffer Cell Logic chip of claim 23 wherein said predetermined logic chip speed is greater than 300 mHz.

25. The integrated circuit Buffer Cell Logic chip of claim 23 wherein said plurality of interconnected logic gates comprise a plurality of interconnected CMOS logic gates and wherein at least some of said plurality of buffers comprise a complementary field effect transistor inverter, including a serially connected N-channel field effect transistor and P-channel field effect transistor, the N-channel and P-channel field effect transistors having predetermined channel widths and channel lengths, said inverter having an input and an output, with the input being connected to the output of the associated logic gate and the output being connected to the associated output connections.

26. The integrated circuit Buffer Cell Logic chip of claim 23 wherein said plurality of interconnected logic gates comprise a plurality of interconnected CMOS logic gates and wherein at least some of the plurality of buffers comprise a plurality of serially connected complementary field effect transistor inverter stages, each comprising a serially connected N-channel field effect transistor and P-channel field effect transistor, the N-channel and P-channel field effect transistors having predetermined channel widths and channel lengths, each of said complementary field effect transistor inverter stages having an input and an output, with the output of the immediately preceding inverter stage being connected to the input of an immediately succeeding inverter stage, the input of the first inverter stage being connected to the output of the associated logic gate, and the output of the last inverter stage being connected to the associated output connections.

27. The integrated circuit Buffer Cell Logic chip of claim 23 wherein said plurality of interconnected logic gates comprise a plurality of interconnected CMOS logic gates and wherein at least some of the plurality of buffers comprise a #complementary integrated bipolar and field effect transistor inverter.

28. The integrated circuit Buffer Cell Logic chip of claim 23 wherein said plurality of interconnected logic gates comprise a plurality of interconnected CMOS logic gates and wherein at least one of said plurality of buffers comprise a plurality of serially connected field effect transistor inverters, each comprising a serially connected N-channel field effect transistor and P-channel field effect transistor, the N-channel and P-channel field effect transistors having predetermined channel widths and channel lengths, each of said complementary field effect transistor inverter stages having an input and an output, with the output of the immediately preceding inverter stage being connected to the input of an immediately succeeding inverter stage, the input of inverter stage being connected to the output of the associated logic gate, and the output of the last inverter stage being connected to the associated output connections, the last of said serially connected field effect transistor stages being a complementary integrated bipolar and field effect transistor inverter stage.

29. The integrated circuit Buffer Cell Logic chip of claim 23 wherein said plurality of interconnected logic gates comprise a plurality of interconnected CMOS logic gates having said predetermined number of serially connected field effect transistors of a first conductivity type and having said predetermined number of parallel connected field effect transistors of second conductivity type, a respective one of said predetermined number of logic gate inputs being connected to a respective one of said serially connected field effect transistors and a respective one of said parallel connected field effect transistors, the channel width of the serially connected field effect transistors being said predetermined number times the channel width of the parallel connected field effect transistors, whereby a symmetric gate transfer function is obtained.

30. The integrated circuit Buffer Cell Logic Chip of claim 25 wherein the N-channel field effect transistor in said inverter has a channel width which is less than a predetermined factor times the width of the N-channel of the CMOS logic gate, whereby said CMOS logic gate drives said inverter at high speed.

31. The integrated Buffer Cell Logic chip of claim 30 wherein the P-channel field effect transistor of the inverter has a channel which is wider than the channel of the N-channel field effect transistor of the inverter step by a second predetermined factor.

32. The integrated circuit Buffer Cell Logic chip of claim 31 wherein said second predetermined factor comprises η

, the ratio of electron mobility in N-channel field effect transistor to hole mobility P-channel field effect transistors.

33. The integrated circuit Buffer Cell Logic chip of claim 30 wherein said predetermined factor is equal to ##EQU44## where I_sat * is the channel saturation current of a square channel field effect transistor having width and length of L_o ;

T_rise is the desired rise time of the integrated circuit Buffer Cell Logic chip;

η

is the ratio of electron mobility in the N-channel to hole mobility in the P-channel;

Cg* is the effective gate capacity of the capacitive load per unit area;

L_o is the channel length for the complementary field effect transistor in the inverter stage;

V_dd is the power supply voltage applied to the integrated circuit Buffer Cell Logic chip;

L_c is the interconnecting conductor length between inverter stages; and

α

_o is equal to Cg*(1+η

)/C_i β

, where C_i is equal to the field oxide insulator capacity per unit area, and β

is equal to the ratio of the width of the interconnecting conductor at the output of the inverter and the width of the N-channel in the inverter.

34. The integrated circuit Buffer Cell Logic chip of claim 26, wherein the N-channel field effect transistor in each inverter stage has a channel width which is less than a predetermined factor times the width of the N-channel of the immediately preceding inverter stage, whereby said buffer drives said capacitive load at high speed.

35. The integrated circuit Buffer Cell Logic chip of claim 34 wherein said logic gate includes at least one N-channel field effect transistor, and wherein the N-channel field effect transistor in the first inverter stage has a channel width which is less than said predetermined factor times the width of the at least one N-channel field effect transistor in the logic gate.

36. The integrated circuit Buffer Cell Logic chip of claim 34 wherein the plurality of serially connected complementary field effect transistor inverter stages comprise an odd number of serially connected complementary field effect transistor stages, whereby the output of the last inverter stage inverts the logic signal at the input of the first inverter stage.

37. The integrated circuit Buffer Cell Logic chip of claim 34 wherein the plurality of serially connected complementary field effect transistor inverter stages comprise an even number of serially connected complementary field effect transistor stages, whereby the output of the last inverter stage does not invert the logic signal at the input of the first inverter stage.

38. The integrated circuit Buffer Cell Logic chip of claim 34 wherein the plurality of serially connected complementary field effect transistor inverter stages comprise an odd number of serially connected complementary field effect transistor stages, whereby the buffer drives the capacitive load with an inverted logic signal from said logic gate.

39. The integrated circuit Buffer Cell Logic chip of claim 34 wherein the plurality of serially connected complementary field effect transistor inverter stages comprise an even number of serially connected complementary field effect transistor stages, whereby the buffer drives the capacitive load with a non-inverted logic signal from said logic gate.

40. The integrated circuit Buffer Cell Logic chip of claim 34 wherein the P-channel field effect transistor of each of the inverter stages has a channel which is wider than the channel of the corresponding N-channel field effect transistor of each inverter stage by a second predetermined factor.

41. The integrated circuit Buffer Cell Logic chip of claim 40 wherein said second predetermined factor comprises η

, the ratio of electron mobility in N-channel field effect transistor to P-channel field effect transistors.

42. The integrated circuit Buffer Cell Logic chip of claim 34 wherein said predetermined factor is equal to ##EQU45## where I_sat * is the channel saturation current of a square channel field effect transistor having width and length of L_o ;

T_rise is the desired rise time of the Ring Segment Buffer;

η

is the ratio of electron mobility in the N-channel to hole mobility in the P-channel;

Cg* is the effective gate capacity of the capacitive load per unit area;

L_o is the channel length for the complementary field effect transistors in the inverter stages;

V_dd is the power supply voltage applied to the Buffer Cell Logic chip;

L_c is the interconnecting conductor length between inverter stages; and

α

_o is equal to Cg*(1+η

)/C_i β

, where C_i is equal to the field oxide insulator capacity per unit area, and β

is equal to the ratio of the width of the interconnecting conductor at the output of the inverter and the width of the first N-channel in the buffer.

43. The integrated Buffer Cell Logic chip of claim 34 wherein the last inverter stage comprises an integrated complementary bipolar transistor and field effect transistor inverter, with the N-channel field effect transistor in the last stage having a gate width which is reduced from the predetermined factor times the gate width of the N-channel of the immediately proceeding stage by a second predetermined factor.

44. The integrated Buffer Cell Logic chip claim 43 wherein the integrated bipolar transistor comprises a Lifetime Controlled bipolar transistor.

45. The integrated Buffer Cell Logic chip of claim 44 wherein said second predetermined factor is about β

/3.25, where β

is the current gain of the Lifetime Controlled bipolar transistor.

46. The integrated Buffer Cell Logic chip of claim 44 wherein the minority carrier lifetime in said Lifetime Controlled bipolar transistor is less than 8e-9 seconds.

47. The integrated Buffer Cell Logic chip claim 46 wherein the minority carrier lifetime is less than ten times the desired high speed rise time.

48. The integrated Buffer Cell Logic chip of claim 46 wherein the Lifetime Controlled bipolar transistor has a current gain of at least twenty.

49. The integrated Buffer Cell Logic chip of claim 44 wherein the base region of the Lifetime Controlled bipolar transistor is doped with gold.

50. The integrated Buffer Cell Logic chip of claim 49 wherein the gold doping density is at least 10e15 cm-3.

51. The integrated Buffer Cell Logic chip of claim 27 wherein the integrated bipolar transistor comprises a Lifetime Controlled bipolar transistor.

52. The integrated Buffer Cell Logic chip of claim 51 wherein the minority carrier lifetime in said Lifetime Controlled bipolar transistor is less than 8e-9 seconds.

53. The integrated Buffer Cell Logic chip of claim 52 wherein the minority carrier lifetime is less than ten times the desired high speed rise time.

54. The integrated Buffer Cell Logic chip of claim 51 wherein the Lifetime Controlled bipolar transistor has a current gain of at least twenty.

55. The integrated Buffer Cell Logic chip of claim 51 wherein the base region of the Lifetime Controlled bipolar transistor is doped with gold.

56. The integrated Buffer Cell Logic chip of claim 55 wherein the gold doping density is at least 10e15 cm-3.

57. A Delay Storage cell comprising:

a memory cell having an input and an output, for storing therein a data value from said input and for providing a stored data value to said output; and

a Delay Ring Segment Buffer coupled to said memory cell output, said Delay Ring Segment Buffer comprising a plurality of serially connected complementary field effect transistor stages, each of said complementary field effect transistor inverter stages comprising a serially connected N-channel field effect transistor and P-channel field effect transistor, the N-channel and P-channel field effect transistors having predetermined channel widths and channel lengths, each of said complementary field effect transistor inverter stages having an input and an output, with the output of an immediately preceding inverter stage being connected to the input of an immediately succeeding inverter stage and the output of the last inverter stage being connected to a capacitive load;

each field effect transistor in the Delay Ring Segment Buffer having a predetermined channel length selected to provide a predetermined delay in said Delay Ring Segment Buffer;

the N-channel field effect transistor in each inverter stage having a channel width which is less than a predetermined factor times the width of the N-channel of the immediately preceding inverter stage;

whereby said Delay Storage cell stores the new input data value therein and provides the previously stored data value at the output of said Delay Ring Segment Buffer until the end of said predetermined delay.

58. The Delay Storage cell of claim 57 wherein said memory cell comprises a cross-coupled pair of complementary field effect transistors.

59. The Delay Storage cell of claim 57 wherein said memory cell further includes a clock input, said memory cell storing therein said new data value from said input upon occurrence of a clock pulse at said clock input;

whereby a single clock input shift register stage is provided.

60. The Delay Storage cell of claim 57 wherein the output of the last inverter stage is connected to said memory cell input to thereby produce a multivibrator.

61. The Delay Storage Cell of claim 57 wherein the output of the last inverter stage is connected to a second Delay Storage cell to produce a delay latch.

62. The Delay Storage cell of claim 57 wherein said capacitive load comprises a first input of a two-input AND gate, said memory input being connected to a second input of said two-input AND gates, to thereby provide a binary counter stage.

63. The Delay Storage cell of claim 57 wherein said memory cell includes at least one N-channel field effect transistor, and wherein the N-channel field effect transistor in the first inverter stage has a channel width which is less than said predetermined factor times the width of the N-channel field effect transistor in the memory cell.

64. The Delay Storage cell of claim 57 wherein the plurality of serially connected complementary field effect transistor inverter stages comprise an odd number of serially connected complementary field effect transistor stages, whereby the output of the last inverter stage inverts the signal at the input of the first inverter stage.

65. The Delay Storage cell of claim 57 wherein the plurality of serially connected complementary field effect transistor inverter stages comprise an even number of serially connected complementary field effect transistor stages, whereby the output of the last inverter stage does not invert the signal at the input of the first inverter stage.

66. The Delay Storage cell of claim 57 wherein the P-channel field effect transistor of each of the inverter stages has a channel which is wider than the channel of the corresponding N-channel field effect transistor of each inverter stage by a second predetermined factor.

67. The Delay Storage cell of claim 66 wherein said second predetermined factor comprises η

, the ratio of electron mobility in N-channel field effect transistor to hole mobility P-channel field effect transistors.

68. The Delay Storage cell of claim 57 wherein said predetermined factor is equal to ##EQU46## where I_sat * is the channel saturation current of a square channel field effect transistor having width and length of L_o ;

T_rise is the desired rise time of the Ring Segment Buffer;

η

is the ratio of electron mobility in the N-channel to hole mobility in the P-channel;

Cg* is the effective gate capacity of the capacitive load per unit area;

L_o is the channel length for the complementary field effect transistors in the inverter stages;

V_dd is the power supply voltage applied to the Ring Segment Buffer;

L_c is the interconnecting conductor length between inverter stages; and

α

_o is equal to Cg*(1+η

)/C_i β

, where C_i is equal to the field oxide insulator capacity per unit area and β

is equal to the ratio of the width of the interconnecting conductor at the output of the inverter and the width of the first N-channel in the Ring Segment Buffer.

69. The Delay Storage cell of claim 57 wherein the last inverter stage comprises an integrated complementary bipolar transistor and field effect transistor inverter, with the N-channel field effect transistor in the last stage having a gate width which is reduced from the predetermined factor times the gate width of the N-channel of the immediately proceeding stage by a second predetermined factor.

70. The Delay Storage cell of claim 69 wherein the integrated bipolar transistor comprises a Lifetime Controlled bipolar transistor.

71. The Delay Storage cell of claim 70 wherein said second predetermined factor is about β

/3.25, where β

is the gain of the Lifetime Controlled bipolar transistor.

72. The Delay Storage cell of claim 70 wherein the minority carrier lifetime in said Lifetime Controlled bipolar transistor is less than 8e-9 seconds.

73. The Delay Storage cell of claim 72 wherein the minority carrier lifetime is less than ten times the desired high speed rise time.

74. The Delay Storage cell of claim 72 wherein the Lifetime Controlled bipolar transistor has a current gain of at least twenty.

75. The Delay Storage cell of claim 70 wherein the base region of the Lifetime Controlled bipolar transistor is doped with gold.

76. The Delay Storage cell of claim 75 wherein the gold doping density is at least 10e15 cm-3.

77. The Delay Storage cell of claim 57 wherein the channel lengths L_o of the complementary field effect transistors in the plurality of serially connected complementary field effect transistor inverters stages are selected to provide a desired delay time T_d according to the following relationship:

space="preserve" listing-type="equation">T.sub.d =0.65 NT.sub.rise

78. An integrated circuit Field Effect Transistor (FET) logic circuit comprising:

a first plurality of FETs of a first conductivity type, each having a control electrode for receiving a logic input signal, said first plurality of FETs of a first conductivity type being connected in parallel between a first potential level and a common output;

a first plurality of FETs of a second conductivity type, each having a control electrode for receiving a logic input signal, said first plurality of FETs of a second conductivity type being connected in series between a second potential level and said common output; and

a first plurality of logic input signals, a respective one of which is connected to a respective one of the control electrodes of the first plurality of FETs of a first conductivity type and a respective one of the control electrodes of the first plurality of FETs of a second conductivity type;

said FETs each having a channel, with the channel in each of said first plurality of FETs of a second conductivity type being said first plurality times wider than the channel in each of said first plurality of FETs of a first conductivity type;

whereby said FET logic circuit has a symmetrical transfer function at said common output.

79. The logic circuit of claim 78 wherein the channel in each of said first plurality of FETs of a first conductivity type is also wider than the channel in said first plurality of FETs of a second conductivity type by the ratio of the hole mobility in the first conductivity type to the hole mobility in the second conductivity type.

80. An integrated circuit bipolar transistor-field effect transistor (BIFET) driver for a capacitive load, comprising:

a bipolar transistor comprising a base of first conductivity type and an emitter and a collector of second conductivity type, one of the collector and emitter being connected to the capacitive load;

a field effect transistor comprising a source and a drain of said first conductivity type;

the drain of said field effect transistor being electrically connected to the base of the bipolar transistor;

the minority carrier lifetime in said base being less than 8e-9 seconds;

whereby the capacitive load is driven at high speed.

81. The BIFET driver of claim 80 wherein said bipolar transistor has a current gain of at least twenty.

82. The BIFET driver of claim 80 wherein said base is doped with gold.

83. The BIFET driver of claim 82 wherein the gold doping density is at least 10e15 cm-3.

84. The BIFET driver of claim 80 wherein said base and said drain are formed in a common region of said first conductivity type.

85. An integrated bipolar transistor complementary metal oxide semiconductor (BICMOS) field effect transistor (FET) driver for a capacitive load, comprising:

a CMOS inverter having an input and an output;

a bipolar transistor complementary emitter follower having an input and an output, the output of said CMOS inverter being electrically connected to the input of said bipolar transistor complementary emitter follower, the output of said bipolar transistor complementary emitter follower being connected to said capacitive load;

the minority carrier lifetime in the base regions of the bipolar transistors complementary emitter follower being less than 8e-9 seconds;

whereby the capacitive load is driven at high speed.

86. The BICMOS driver of claim 85:

wherein said CMOS inverter comprises a pair of complementary field effect transistors, the sources and drains of which are serially connected between first and second electrical potentials, the gates of which are electrically connected to provide said CMOS inverter input;

wherein said bipolar transistor complementary emitter follower comprises a pair of complementary bipolar transistors, the emitters and collectors of which are serially connected between the first and second electrical potential, and the output being a common connection between the serially connected bipolar transistors;

the drain of one of the pair of complementary field effect transistors being of first conductivity type and the drain of the other of the pair of complementary transistors being of second conductivity type;

the base of one of the pair of complementary bipolar transistors being said first conductivity type and the base of the other of the pair of complementary bipolar transistors being said second conductivity type;

the drain of the first conductivity type being electrically connected to the base of the first conductivity type, and the drain of the second conductivity type being connected to the base of the second conductivity type.

87. The BICMOS driver of claim 85 wherein the bipolar transistors in the complementary emitter follower have a current gain of at least twenty.

88. The BICMOS driver of claim 85 wherein the bases of the bipolar transistor emitter follower are doped with gold.

89. The BICMOS driver of claim 85 wherein the gold doping density is at least 10e15 cm-3.

90. The BICMOS driver of claim 86 wherein the base and drain of said first conductivity type are formed in a first common region of said first conductivity type;

and wherein the base and drain of second conductivity type are formed in a second common region of said second conductivity type.