Semiconductor diffusion strain gage

• US 4,841,272 A
• Filed: 08/26/1987
• Issued: 06/20/1989
• Est. Priority Date: 09/25/1986
• Status: Expired due to Fees

• Current Assignee: Yokogawa Electric Corporation
• Original Assignee: Yokogawa Electric Corporation
• Inventors: Nomiyama, Mayumi, Yamagishi, Hideaki
• Primary Examiner(s): Goldberg, E. A.
• Assistant Examiner(s): Lateef, M. M.
• Application Number:
  US07/089,504
• Time in Patent Office: 664 Days
• Field of Search: 338/2-5, 29/621.1, 29/569.1, 29/25.35
• 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: Y10T 29/49103 Strain gauge making

Abstract

A strain gage wherein neutral impurity atoms forming neither donors nor acceptors are doped in a silicon substrate and a diffused resistance element is formed in the doped region, thereby decreasing the temperature coefficient of resistivity without changing the resistivity and decreasing the temperature coefficient of piezoresistance coefficient with no effect on the piezoresistance coefficient which governs the sensitivity of the strain gage.

Claims

1. A semiconductor strain gage comprising a silicon substrate, wherein impurity atoms of the IV group forming neither donors nor acceptors are doped in said silicon substrate, and wherein a diffused resistance region is formed in the impurity doped region.

2. The gage of claim 1, wherein said impurity atom is germanium, and said diffused resistance region is formed of boron.

3. A method of forming a semiconductor diffused resistance type strain gage comprising the steps of

doping germanium into a surface of a silicon substrate;

diffusing a layer of boron into the germanium diffused layer;

diffusing a layer of silicon dioxide on the boron layer;

forming holes in said silicon dioxide layer; and

forming electrodes within said holes.