Semiconductor piezoresistor

• US 6,441,716 B1
• Filed: 06/12/2001
• Issued: 08/27/2002
• Est. Priority Date: 02/08/2000
• Status: Expired due to Term

• Current Assignee: Pall Corporation (Danaher Corporation)
• Original Assignee: BIOflex Medical Magnetics, Inc. (Bionoid Pharma, Inc.)
• Inventors: Moustakas, Theodore D., Tuller, Harry L., Doppalapudi, Dharanipal, Mlcak, Richard
• Primary Examiner(s): Easthom, Karl D.
• Application Number:
  US09/879,692
• Publication Number:
  US 20020070841A1
• Time in Patent Office: 441 Days
• Field of Search: 338/2, 338/5, 338/47, 338/101, 257/417, 296/101, 296/20, 296/21
• US Class Current: 338/2
• CPC Class Codes: G01L 1/2293 of the semi-conductor type semi-conductor devices controllable by variations of applied mechanical force H01L29/84
• CPC Class Codes: H01L 29/155 Comprising only semiconductor materials H01L29/154 takes precedence
• CPC Class Codes: Y10T 29/49099 Coating resistive material on a base
• CPC Class Codes: Y10T 29/49101 Applying terminal

Abstract

A piezoresistor having a base substrate with a quantum well structure formed on the base substrate. The quantum well structure includes at least one quantum well layer bounded by barrier layers. The barrier layers are formed from a material having a larger bandgap than the at least one quantum well layer.

Claims

1. A piezoresistor comprising:

a base substrate; and

a quantum well structure formed in combination with the base substrate, the quantum well structure comprising at least one smaller bandgap layer bounded by larger bandgap layers, the at least one smaller bandgap layer having a thickness of 30 Å

or less.

2. The piezoresistor of claim 1 in which the at least one smaller bandgap is a quantum well layer and the larger bandgap layers are barrier layers.

3. The piezoresistor of claim 1 in which each smaller bandgap layer is 5 Å

to 30 Å

thick.

4. The piezoresistor of claim 1 in which the larger bandgap layers in the quantum well structure are more than 5 Å

thick.

5. The piezoresistor of claim 1 in which the larger bandgap layers are 5 Å

to 50 Å

thick.

6. The piezoresistor of claim 1 in which quantum confinement of carriers is achieved in the at least one smaller bandgap layer.

7. The piezoresistor of claim 2 in which the quantum well structure has 5 to 10 quantum well layers.

8. The piezoresistor of claim 1 in which the base substrate is a single crystal.

9. The piezoresistor of claim 1 in which the base substrate is a mechanical element of a sensor.

10. The piezoresistor of claim 9 in which the mechanical element is micromachined.

11. The piezoresistor of claim 1 in which the base substrate is a thin film.

12. The piezoresistor of claim 2 in which the barrier layers are formed from an insulating material.

13. A piezoresistor comprising:

a single crystal base substrate; and

a quantum well structure formed in combination with the base substrate, the quantum well structure having alternating larger and smaller bandgap semiconductor layers, wherein quantum confinement of carriers is achieved in the smaller bangap layers, the smaller bandgap layers having a thickness of 30 Å

or less.

14. A method of forming a piezoresistor comprising:

providing a base substrate; and

forming a quantum well structure in combination with the base substrate, the quantum well structure comprising at least one smaller bandgap layer bounded by larger bandgap layers, the at least one smaller bandgap layer having a thickness of 30 Å

or less.

15. The method of claim 14 further comprising forming at least one quantum well layer from the smaller bandgap layer and barrier layers from the larger bandgap layers.

16. The method of claim 14 further comprising forming the at least one smaller bandgap layer with a thickness of 5 Å

to 30 Å

.

17. The method of claim 14 further comprising forming the larger bandgap layers more than 5 Å

thick.

18. The method of claim 17 further comprising forming the larger bandgap layers 5 Å

to 50 Å

thick.

19. The method of claim 15 further comprising forming 5 to 10 quantum well layers in the quantum well structure.

20. The method of claim 14 further comprising forming the base substrate from a single crystal.

21. The method of claim 14 further comprising forming the base substrate from a mechanical element of a sensor.

22. The method of claim 21 further comprising micromachining the mechanical element.

23. The method of claim 14 further comprising forming the base substrate from a film.

24. A method of forming a piezoresistor comprising:

providing a single crystal base substrate; and

forming a quantum well structure in combination with the base substrate, the quantum well structure having alternating larger and smaller bandgap semiconductor layers, wherein quantum confinement of carriers is achieved in the smaller band gap layers, the smaller bandgap layers having a thickness of 30 Å

or less.