Semiconductor pressure sensor

• US 6,880,406 B2
• Filed: 08/13/2003
• Issued: 04/19/2005
• Est. Priority Date: 05/28/2003
• Status: Active Grant

• Current Assignee: China Star Optoelectronics International (HK) Limited (TCL Technology Group Corp.)
• Original Assignee: AU Optronics Corporation
• Inventors: Yang, Chien-Sheng
• Primary Examiner(s): OEN, WILLIAM L
• Application Number:
  US10/604,723
• Publication Number:
  US 20040237661A1
• Time in Patent Office: 615 Days
• Field of Search: 737/06, 737/54, 737/56, 73715-727, 29/254.1, 29/254.2, 257/347, 257/352, 257/353, 257/354, 257 66- 69, 257/57, 257/72, 257/350
• US Class Current: 73/754
• CPC Class Codes: G01L 9/0055 bonded on a diaphragm

Abstract

A semiconductor pressure sensor comprises a non-single-crystal-silicon-based substrate, a movable insulating diaphragm, at least one piezoresistor positioned on the insulating diaphragm, an insulating supporter positioned on the non-single-crystal-silicon-based substrate for fixing two ends of the insulating diaphragm and forming a cavity between the insulating diaphragm and the non-single-crystal-silicon-based substrate, and a thin film transistor (TFT) control circuit positioned on the non-single-crystal-silicon-based substrate and electrically connected to the insulating diaphragm and the piezoresistor.

Claims

1. A semiconductor pressure sensor comprising:

a non-single-crystal-silicon-based substrate;

a movable insulating diaphragm;

at least one piezoresistor positioned on the insulating diaphragm;

an insulating supporter positioned on the non-single-crystal-silicon-based substrate for fixing two ends of the insulating diaphragm and forming a cavity between the insulating diaphragm and the non-single-crystal-silicon-based substrate; and

a thin film transistor (TFT) control circuit positioned on the non-single-crystal-silicon-based substrate and electrically connected to the insulating diaphragm and the piezoresistor.

2. The semiconductor pressure sensor of claim 1 wherein the non-single-crystal-silicon-based substrate is a glass substrate.

3. The semiconductor pressure sensor of claim 2 wherein the TFT control circuit is a low temperature polysilicon TFT control circuit.

4. The semiconductor pressure sensor of claim 1 wherein the non-single-crystal-silicon-based substrate is a quartz substrate.

5. The semiconductor pressure sensor of claim 4 wherein the TFT control circuit is a high temperature polysilicon TFT control circuit.

6. The semiconductor pressure sensor of claim 1 wherein the insulating diaphragm and the insulating supporter are formed simultaneously.

7. The semiconductor pressure sensor of claim 6 wherein the insulating diaphragm and the insulating supporter both comprise silicon dioxide.

8. The semiconductor pressure sensor of claim 1 wherein the piezoresistor comprises doped polysilicon.

9. The semiconductor pressure sensor of claim 1 wherein the piezoresistor comprises a piezoelectric thin film.

10. The semiconductor pressure sensor of claim 9 wherein the piezoelectric thin film comprises ZnO, BaTiO₃, or PbZrTiO₃ (PZT).

11. The semiconductor pressure sensor of claim 1 wherein the non-single-crystal-silicon-based substrate further comprises a thin film transistor display region for displaying a variation of pressure detected by the semiconductor pressure sensor.

12. A semiconductor pressure sensor comprising:

an insulating substrate;

a movable insulating diaphragm;

a piezoresistor positioned on the insulating diaphragm;

an insulating supporter positioned on the insulating substrate for fixing two ends of the insulating diaphragm and forming a cavity between the insulating diaphragm and the insulating substrate; and

a control circuit electrically connected to the insulating diaphragm and the piezoresistor.

13. The semiconductor pressure sensor of claim 12 wherein the insulating diaphragm and the insulating supporter are formed simultaneously.

14. The semiconductor pressure sensor of claim 12 wherein the insulating diaphragm and the insulating supporter both comprise silicon dioxide.

15. The semiconductor pressure sensor of claim 12 wherein the piezoresistor comprises doped polysilicon.

16. The semiconductor pressure sensor of claim 12 wherein the piezoresistor is a piezoelectric thin film.

17. The semiconductor pressure sensor of claim 16 wherein the piezoelectric thin film comprises ZnO, BaTiO₃, or PbZrTiO₃ (PZT).

18. The semiconductor pressure sensor of claim 12 wherein the insulating substrate is a glass substrate.

19. The semiconductor pressure sensor of claim 18 wherein the control circuit is positioned on the glass substrate and the control circuit comprises a low temperature polysilicon thin film transistor control circuit.

20. The semiconductor pressure sensor of claim 12 wherein the insulating substrate is a quartz substrate.

21. The semiconductor pressure sensor of claim 20 wherein the control circuit is positioned on the quartz substrate and the control circuit comprises a high temperature polysilicon thin film transistor control circuit.

22. The semiconductor pressure sensor of claim 12 wherein the control circuit is positioned on a printed circuit board (PCB) electrically connected to the insulating diaphragm and the piezoresistor via a flexible printed circuit (FPC) board.

23. The semiconductor pressure sensor of claim 12 wherein the control circuit is positioned on a flexible printed circuit (FPC) board, the control circuit being electrically connected to the insulating diaphragm and the piezoresistor via the flexible printed circuit board.

24. The semiconductor pressure sensor of claim 12 wherein the insulating substrate further comprises a thin film transistor display region for displaying a variation of pressure detected by the semiconductor pressure sensor.