STACKED FIELD-EFFECT TRANSISTOR SWITCH

• US 20180145678A1
• Filed: 11/17/2017
• Published: 05/24/2018
• Est. Priority Date: 11/18/2016
• Status: Active Grant

• Current Assignee: Qorvo US, Inc. (Qorvo, Inc.)
• Original Assignee: Qorvo US, Inc. (Qorvo, Inc.)
• Inventors: Maxim, George, Leipold, Dirk Robert Walter, Costa, Julio C., Granger-Jones, Marcus, Scott, Baker
• Granted Patent: US 10,749,518 B2
• Time in Patent Office: Days
• CPC Class Codes: H01L 21/823807 with a particular manufacturing method of the channel structures, e.g. channel implants, halo or pocket implants, or channel materials
• CPC Class Codes: H01L 23/4824 Pads with extended contours, e.g. grid structure, branch structure, finger structure
• CPC Class Codes: H01L 23/4825 for devices consisting of semiconductor layers on insulating or semi-insulating substrates, e.g. silicon on sapphire devices, i.e. SOS
• CPC Class Codes: H01L 23/66 High-frequency adaptations
• CPC Class Codes: H01L 27/0629 in combination with diodes, or resistors, or capacitors
• CPC Class Codes: H01L 27/092 complementary MIS field-effect transistors
• CPC Class Codes: H01L 27/1203 the substrate comprising an insulating body on a semiconductor body, e.g. SOI three-dimensional layout H01L27/0688
• CPC Class Codes: H01L 28/60 Electrodes
• CPC Class Codes: H01L 29/0692 Surface layout
• CPC Class Codes: H01L 29/1054 with a variation of the composition, e.g. channel with strained layer for increasing the mobility
• CPC Class Codes: H03K 17/063 in field-effect transistor switches
• CPC Class Codes: H03K 17/102 in field-effect transistor switches
• CPC Class Codes: H03K 17/122 in field-effect transistor switches
• CPC Class Codes: H03K 17/161 in field-effect transistor switches
• CPC Class Codes: H03K 17/162 without feedback from the output circuit to the control circuit

Abstract

A stacked field-effect transistor (FET) switch is disclosed. The stacked FET switch has a first FET device stack that is operable in an on-state and in an off-state and is made up of a first plurality of FET devices coupled in series between a first port and a second port, wherein the first FET device stack has a conductance that decreases with increasing voltage between the first port and the second port. The stacked FET switch also includes a second FET device stack that is operable in the on-state and in the off-state and is made up of a second plurality of FET devices coupled in series between the first port and the second port, wherein the second FET device stack has a conductance that increases with increasing voltage between the first port and the second port.

Claims

1. A stacked field-effect transistor (FET) switch comprising:

a first FET device stack that is operable in an on-state and in an off-state, the first FET device stack comprising a first plurality of FET devices coupled in series between a first port and a second port and having a conductance that decreases with increasing voltage between the first port and the second port between 10% and 99% of a first breakdown voltage of the first FET device stack; and

a second FET device stack that is operable in the on-state and in the off-state, the second FET device stack comprising a second plurality of FET devices coupled in series between the first port and the second port and having a conductance that increases with increasing voltage between the first port and the second port between 10% and 99% of a second breakdown voltage of the second FET device stack.

2. The stacked FET switch of claim 1 wherein the second plurality of FET devices comprises ballistic FET devices.

3. The stacked FET switch of claim 1 wherein the first plurality of FET devices comprises N-channel FET devices and the second plurality of FET devices comprises P-channel FET devices.

4. The stacked FET switch of claim 3 wherein the P-channel FET devices are germanium doped to enhance carrier mobility.

5. The stacked FET switch of claim 1 wherein the first plurality of FET devices comprises N-channel FET devices and the second plurality of FET devices comprises N-channel FET devices.

6. The stacked FET switch of claim 1 wherein each of the first plurality of FET devices is coupled in parallel with a corresponding one of the second plurality of FET devices.

7. The stacked FET switch of claim 1 further comprising a plurality of capacitors wherein each of the plurality of capacitors is coupled in parallel with a corresponding one of the second plurality of FET devices such that parasitic capacitances of the first plurality of FET devices and the second plurality of FET devices cause a total capacitance of the stacked FET switch to deviate by no more ±

5% while the stacked FET switch is in an open state.

8. The stacked FET switch of claim 7 wherein the plurality of capacitors comprises metal-insulator-metal type capacitors.

9. The stacked FET switch of claim 1 further comprising a first bias circuitry having a first output coupled to first control terminals of the first plurality of FET devices and a second bias circuitry having a second bias output coupled to second control terminals of the second plurality of FET devices.

10. The stacked FET switch of claim 9 wherein the first bias circuitry and the second bias circuitry are each configured to automatically adjust bias voltage level to track with changes in supply voltage.

11. The stacked FET switch of claim 9 wherein the first bias circuitry and the second bias circuitry are each configured to automatically adjust bias voltage level to track with changes in temperature.

12. The stacked FET switch of claim 9 wherein the first bias circuitry and the second bias circuitry are each configured to automatically adjust bias voltage level to track with changes in supply voltage and changes in temperature.

13. The stacked FET switch of claim 9 wherein the first bias circuitry is configured to generate a first bias voltage level that is different from a second bias voltage level generated by the second bias circuitry.

14. The stacked FET switch of claim 1 wherein the second plurality of FET devices comprises fewer FET devices than the first plurality of FET devices.

15. The stacked FET switch of claim 14 wherein there is one FET device of the second plurality of FET devices coupled in parallel across for every two FET devices of the first plurality of FET devices beginning with two FET devices of the first plurality of FET devices closest to the first port.

16. The stacked FET switch of claim 15 further including a third plurality of FET devices having an equal number of FET devices as the second plurality of FET devices, wherein there is one FET device of the third plurality of FET devices coupled in parallel across for every two FET devices of the first plurality of FET devices beginning with two FET devices of the first plurality of FET devices closest to the second port.

17. The stacked FET switch of claim 1 wherein the first plurality of FET devices and the second plurality of FET devices are of the silicon-on-insulator type.

18. The stacked FET switch of claim 1 further comprising:

a polymeric substrate; and

a device layer within which the first FET device stack and the second FET stack reside, wherein the device layer is directly supported by the polymeric substrate.

19. The stacked FET switch of claim 1, wherein at least 50% carrier transport of the first plurality of FET devices is drift transport and at least 70% of carrier transport of the second plurality of FET devices is ballistic transport.

20. The stacked FET switch of claim 1 wherein the physical size of the second plurality of FET devices is different from the physical size of the first plurality of FET devices.

21. The stacked FET switch of claim 1 wherein each of the first plurality of FET devices has a first number of gate fingers and each of the second plurality of FET devices has a second number of gate fingers that is different in number from the first number of gate fingers.