Titanium bolometer-type infrared detecting apparatus

• US 5,698,852 A
• Filed: 08/11/1995
• Issued: 12/16/1997
• Est. Priority Date: 08/11/1994
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Tanaka, Akio, Teranishi, Nobukazu
• Primary Examiner(s): Hannaher, Constantine
• Assistant Examiner(s): Tyler, Virgil O.
• Application Number:
  US08/514,256
• Time in Patent Office: 858 Days
• Field of Search: 250/332, 250/338.4, 250/370.14, 250/370.15, 348/294, 348/301, 348/308, 348/320
• US Class Current: 250/332
• CPC Class Codes: G01J 5/22 Electrical features thereof

Abstract

In a bolometer-type infrared detecting apparatus, a bolometer and a MOS transistor are provided for one pixel. A source of the MOS transistor is connected to a power supply terminal. A drain of the MOS transistor is connected to the bolometer which is connected via a switch to an output terminal.

Claims

1. A bolometer-type infrared detecting apparatus comprising:

a power supply terminal;

an output terminal;

a MOS transistor having a source connected to said power supply terminal, a drain and a gate;

a bolometer, operatively connected between said drain and said output terminal, for converting incident infrared into an electrical signal; and

driving means for driving said MOS transistor.

2. An apparatus as set forth in claim 1, wherein said bolometer is made of titanium.

3. An apparatus as set forth in claim 2, wherein said bolometer consists of titanium or an alloy of titanium.

4. An apparatus as set forth in claim 1, wherein said bolometer is thermally isolated from said power supply terminal, said output terminal, said MOS transistor and said driving means.

5. An apparatus as set forth in claim 1, further comprising:

a semiconductor substrate having said source and said drain of said MOS transistor therein; and

an insulating layer formed over said semiconductor substrate and having a cavity therein,

said bolometer being formed on said insulating layer above said cavity thereof.

6. An apparatus as set forth in claim 5, wherein said bolometer is of a folded structure on said insulating layer.

7. An apparatus as set forth in claim 5, further comprising a conductive layer over said semiconductor substrate between said source and said drain of said MOS transistor,

said conductive layer serving as said gate of said MOS transistor.

8. An apparatus as set forth in claim 7, wherein said conductive layer is of a folded structure.

9. An apparatus as set forth in claim 7, wherein said conductive layer is made of polycrystalline silicon.

10. An apparatus as set forth in claim 1, further comprising:

a semiconductor substrate having said source and said drain of said MOS transistor; and

a diaphragm formed in a floating state from said semiconductor substrate;

said bolometer being formed on said diaphragm.

11. An apparatus as set forth in claim 10, wherein said bolometer is of a folded structure on said diaphragm.

12. An apparatus as set forth in claim 10, further comprising a conductive layer over said semiconductor substrate between said source and said drain of said MOS transistor,

said conductive layer serving as said gate of said first MOS transistor.

13. An apparatus as set forth in claim 12, wherein said conductive layer is of a folded structure.

14. An apparatus as set forth in claim 12, wherein said conductive layer is made of polycrystalline silicon.

15. An apparatus as set forth in claim 1, further comprising an integrator circuit connected to said output terminal.

16. An apparatus as set forth in claim 15, wherein said integrator circuit comprises:

a bipolar transistor having an emitter connected to said output terminal, a base for receiving an integration time period signal, and a collector;

a capacitor connected to said collector; and

a reset transistor, connected to said capacitor and being turned ON by a reset signal.

17. An apparatus as set forth in claim 15, wherein said integrator circuit comprises:

a junction type FET having a source connected to said output terminal, a gate for receiving an integration time period signal, and a drain;

a capacitor connected to said drain of said junction type FET; and

a reset transistor, connected to said capacitor and being turned ON by a reset signal.

18. A two-dimensional bolometer-type infrared detecting apparatus comprising:

a power supply terminal;

a plurality of first signal lines arranged along a first direction;

a plurality of second signal lines arranged along a second direction approximately perpendicular to said first direction;

a plurality of source lines arranged along said second direction and connected to said power supply terminal; and

a plurality of pixels,

each of said pixels comprising;

a first MOS transistor having a source connected to one of said source lines, a gate connected to one of said first signal lines, and a drain; and

a bolometer connected between said drain of said first MOS transistor and one of said second signal lines.

19. An apparatus as set forth in claim 18, further comprising:

an output terminal; and

a plurality of transfer gates connected between said second signal lines and said output terminal.

20. An apparatus as set forth in claim 19, further comprising:

a first selecting means, connected to said first signal lines, for selecting one of said first signal lines and applying a first voltage to a selected one of said first signal lines; and

second selecting means, connected to said transfer gates, for selecting one of said transfer gates so that one of said second signal lines is electrically connected to said output terminal.

21. An apparatus as set forth in claim 20, wherein a timing of said second selecting means is delayed from a timing of said first selecting means.

22. An apparatus as set forth in claim 19, wherein an electrical path via any of said pixels is approximately diagonal within said pixels.

23. An apparatus as set forth in claim 22, wherein the width of said second signal lines is approximately the same as that of said source lines, and the width of a conductor connected to said power supply terminal is approximately the same as that of a conductor connected to said output terminal.

24. An apparatus as set forth in claim 18, further comprising:

an output terminal connected to said second signal lines;

a plurality of second MOS transistors connected between said source lines and said power supply line.

25. An apparatus as set forth in claim 24, further comprising:

first selecting means, connected to said first signal lines, for selecting one of said first signal lines and applying a first voltage to a selected one of said first signal lines; and

second selecting means, connected to said second MOS transistors, for selecting one of said second MOS transistors so that one of said source lines is electrically connected to said power supply line.

26. Art apparatus as set forth in claim 25, wherein a timing of said second selecting means is delayed from a timing of said first selecting means.

27. An apparatus as set forth in claim 25, wherein said power supply terminal and said output terminal are diagonally located in relation to each other with respect to said apparatus.

28. An apparatus as set forth in claim 18, further comprising:

a plurality of output terminals; and

a plurality of groups of transfer gates each group connected between one group of said second signal lines and one of said output terminals.

29. An apparatus as set forth in claim 28, further comprising:

first selecting means, connected to said first signal lines, for selecting one of said first signal lines and applying a first voltage to a selected one of said first signal lines; and

second selecting means, connected to said transfer gates, for selecting one of each group of said transfer gates so that one of each group of said second signal lines is electrically connected to one of said output terminals.

30. An apparatus as set forth in claim 29, wherein a timing of said second selecting means is delayed from a timing of said first selecting means.

31. An apparatus as set forth in claim 28, wherein an electrical path via any of pixels is approximately diagonal within said pixels.

32. An apparatus as set forth in claim 31, wherein the width of said second signal lines is approximately the same as that of said source lines, and the width of a conductor connected to said power supply terminal is approximately the same as that of a conductor connected to said output terminal.

33. An apparatus as set forth in claim 32, further comprising:

first selecting means, connected to said first signal lines, for selecting one of said first signal lines and applying a first voltage to a selected one of said first signal lines; and

second selecting means, connected to said second MOS transistors, for selecting one of each group of said second MOS transistors so that one of each group of said source lines is electrically connected to said power supply line.

34. An apparatus as set forth in claim 33, wherein a timing of said second selecting means is delayed from a timing of said first selecting means.

35. An apparatus as set forth in claim 33, wherein said power supply terminal and said output terminal are diagonally located in relation to each other with respect to said apparatus.

36. An apparatus as set forth in claim 18, further comprising:

a plurality of output terminals each group connected to one group of said second signal lines; and

a plurality of second MOS transistors connected between said source lines and said power supply line.

37. An apparatus as set forth in claim 18, wherein said bolometer is made of titanium.

38. An apparatus as set forth in claim 37, wherein said bolometer consists of titanium or an alloy of titanium.

39. An apparatus as set forth in claim 18, wherein said first signal lines are made of polycrystalline silicon, and said second signal lines and said source lines are made of aluminum.

40. A one-dimensional bolometer-type infrared detecting apparatus comprising:

a power supply terminal;

an output terminal;

a first signal line connected to said output terminal and arranged along a first direction;

a plurality of second signal lines arranged along a second direction approximately perpendicular to said first direction;

a source terminal connected to said power supply line and arranged along said first direction; and

a plurality of pixels,

each of said pixels comprising;

a MOS transistor having a source connected to said source line, a gate connected to one of said second signal lines, and a drain; and

a bolometer connected between said drain of said MOS transistor and said first signal line.

41. An apparatus as set forth in claim 40, further comprising selecting means, connected to said second signal lines, for selecting one of said second signal lines and applying a voltage to a selected one of said second signal lines.

42. An apparatus as set forth in claim 40, wherein said bolometer is made of titanium.

43. An apparatus as set forth in claim 42, wherein said bolometer consists of titanium or an alloy of titanium.

44. A one-dimensional bolometer-type infrared detecting apparatus comprising:

a power supply terminal;

a plurality of output terminals;

a plurality of first signal lines each connected to one of said output terminals and arranged along a first direction;

a plurality of second signal lines arranged along a second direction approximately perpendicular to aid first direction;

a source line connected to said power supply line and arranged along said first direction; and

a plurality of pixels,

each of said pixels comprising;

a MOS transistor having a source connected to said source line, a gate connected to one of said second signal lines, and a drain; and

a bolometer connected between said drain of said MOS transistor and one of said first signal lines.

45. An apparatus as set forth in claim 44, further comprising selecting means, connected to said second signal lines, for selecting one of said second signal lines and applying a voltage to a selected one of said second signal lines.

46. An apparatus as set forth in claim 44, wherein said bolometer is made of titanium.

47. An apparatus as set forth in claim 46, wherein said bolometer consists of titanium or an alloy of titanium.

48. A two-dimensional bolometer-type infrared detecting apparatus comprising:

a power supply terminal;

an output terminal arranged diagonally with respect to said power supply terminal;

a plurality of first signal lines arranged along a first direction;

a plurality of second signal lines arranged along a second direction approximately perpendicular to said first direction;

a plurality of source lines connected to said power supply terminal and arranged along said second direction;

a plurality of pixels, each including a MOS transistor having a source connected to one of said source lines, a gate connected to one of said first signal lines, and a titanium bolometer connected between a drain of said MOS transistor and one of said second signal lines;

a plurality of transfer gates connected between said second signal lines and said output terminal;

vertical shift register means operatively connected to said first signal lines, for receiving a vertical synchronization signal and a first horizontal synchronization signal to apply a first voltage having a time period of said first horizontal synchronization signal successively to said first signal lanes in response to said vertical synchronization signals; and

horizontal shift register means, operatively connected to said transfer gates, for receiving a second horizontal synchronization signal and a synchronization clock signal to apply a second voltage having a time period of said synchronization clock signal successively to said transfer gates in response to said second horizontal synchronization signal,

said second horizontal synchronization signal being a delayed signal of said first horizontal synchronization signal.

49. A two-dimensional bolometer-type infrared detecting apparatus comprising:

a power supply terminal;

an output terminal arranged diagonally with respect to said power supply terminal;

a plurality of first signal lines arranged along a first direction;

a plurality of second signal lines connected to said output terminal and arranged along a second direction approximately perpendicular to said first direction;

a plurality of source lines arranged along said second direction;

a plurality of pixels, each including a first MOS transistor having a source connected to one of said source lines, a gate connected to one of said first signal lines, and a titanium bolometer connected between a drain of said first MOS transistor and one of said second signal lines;

a plurality of second MOS transistors connected between said source lines and said power supply line;

vertical shift register means, operatively connected to said first signal lines, for receiving a vertical synchronization signal and a first horizontal synchronization signal to apply a first voltage having a time period of said first horizontal synchronization signal successively to said first signal lines in response to said vertical synchronization signals; and

horizontal shift register means, operatively connected to said second MOS transistors, for for receiving a second horizontal synchronization signal and a synchronization clock signal to apply a second voltage having a time period of said synchronization clock signal successively to said second MOS transistors in response to said second horizontal synchronization signal,

said second horizontal synchronization signal being a delayed signal of said first horizontal synchronization signal.

50. A two-dimensional bolometer-type infrared detecting apparatus comprising:

a power supply terminal;

two output terminals arranged diagonally with respect to said power supply terminal;

a plurality of first signal lines arranged along a first direction;

a plurality of second signal lines arranged along a second direction approximately perpendicular to said first direction;

a plurality of source lines connected to said power supply terminal and arranged along said second direction;

a plurality of pixels, each including a MOS transistor having a source connected to one of said source lines, a gate connected to one of said first signal lines, and a titanium bolometer connected between a drain of said MOS transistor and one of said second signal lines;

two groups of transfer gates each groups connected between one group of said second signal lines and one of said output terminals;

vertical shift register means, operatively connected to said first signal lines, for receiving a vertical synchronization signal and a first horizontal synchronization signal to apply a first voltage having a time period of said first horizontal synchronization signal successively to said first signal lines in response to said vertical synchronization signals;

a horizontal shift register means for receiving a second horizontal synchronization signal and a synchronization clock signal to generate horizontal signals having a time period twice that of said synchronization clock signal successively in response to said second horizontal synchronization signal, said second horizontal synchronization signal being a delayed signal of said first horizontal synchronization signal; and

latch means, connected between said transfer gates and said horizontal shift register means, for latching said horizontal signals in response to a strobe signal having half the frequency of said synchronization clock signal, to apply a second voltage having a time period twice that of said synchronization clock signal successively to each group of said transfer gates.

51. An apparatus as set forth in claim 50, wherein said latch means is caused to be in a through state, to apply said horizontal signals to said transfer gates.

52. A two-dimensional bolometer-type infrared detecting apparatus comprising:

a power supply terminal;

two output terminals arranged diagonally with respect to said power supply terminal;

a plurality of first signal lines arranged along a first direction;

two groups of second signal lines arranged along a second direction approximately perpendicular to said first direction each group of said second signal lines being connected to one of said output terminals;

a plurality of source lines arranged along said second direction;

a plurality of pixels, each including a first MOS transistor having a source connected to one of said source lines, a gate connected to one of said first signal lines, and a titanium bolometer connected between a drain of said first MOS transistor and one of said second signal lines;

a plurality of second MOS transistors connected between said source lines and said power supply line;

vertical shift register means operatively connected to said first signal lines, for receiving a vertical synchronization signal and a first horizontal synchronization signal to apply a first voltage having a time period of said first horizontal synchronization signal successively to said first signal lines in response to said vertical synchronization signals;

horizontal shift register means for receiving a second horizontal synchronization signal and a synchronization clock signal to generate horizontal signals having a time period twice that of said synchronization clock signal successively in response to said second horizontal synchronization signal, said second horizontal synchronization signal being a delayed signal of said first horizontal synchronization signal; and

latch means, connected between said second MOS transistors and said horizontal shift register means, for latching said horizontal signals in response to a strobe signal having half of the frequency of said synchronization clock signal, to apply a second voltage having a time period twice that of said synchronization clock signal successively to said second MOS transistors.

53. A one-dimensional bolometer-type infrared detecting apparatus comprising:

a power supply terminal;

an output terminal;

a first signal line connected to said output terminal and arranged along a first direction;

a plurality of second signal lines arranged along a second direction approximately perpendicular to said first direction;

a source line connected to said power supply line and arranged along said first direction;

a plurality of pixels, each including a MOS transistor having a source connected to said source line, a gate connected to one of said second signal lines, and a titanium bolometer connected between a drain of said transistor and said first signal line;

horizontal shift register means, operatively connected to said second signal lines, for receiving a horizontal synchronization signal and a synchronization clock signal to apply a voltage having a time period of said synchronization lock signal successively to said second signal lines in response to said horizontal synchronization signal.

54. A one-dimensional bolometer-type infrared detecting apparatus comprising:

a power supply terminal;

two output terminals;

two first signal lines each connected to one of said output terminals, said first signal lines being arranged along a first direction;

a plurality of second signal lines arranged along a second direction approximately perpendicular to said first direction;

a source line connected to said power supply line and arranged along said first direction;

a plurality of pixels, each including a MOS transistor having a source connected to said source line, a gate connected to one of said second signal lines, and a titanium bolometer connected between a drain of said MOS transistor and said first signal line;

a horizontal shift register for receiving a horizontal synchronization signal and a synchronization clock signal to generate horizontal signals having a time period twice that of said synchronization lock signal in response to said horizontal synchronization signal; and

latch means, connected between said second signal lines and said horizontal shift register, for latching said horizontal signals in response to a strobe signal having half of the frequency of said synchronization clock signal, to apply a second voltage having a time period twice that of said synchronization clock signal successively to said second signal lines.

55. An infrared detecting apparatus comprising a bolometer consisting of titanium or an alloy of titanium.