Semiconductor device with electric converter element

• US 6,329,696 B1
• Filed: 06/11/1998
• Issued: 12/11/2001
• Est. Priority Date: 06/11/1997
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Tanaka, Akio
• Primary Examiner(s): Bowers, Charles
• Assistant Examiner(s): Kebede, Brook
• Application Number:
  US09/095,590
• Time in Patent Office: 1,279 Days
• Field of Search: 257/417, 257/419, 257/426, 257/431, 257/432, 257/443, 257/444, 257/454, 257/455, 250/338.4, 250/332, 250/370.14, 250/370.15, 348/294, 348/301, 348/308, 348/320, 438/50-53, 737/54, 735/142
• US Class Current: 257/419
• CPC Class Codes: G01F 1/6845 Micromachined devices
• CPC Class Codes: G01J 5/046 Materials; Selection of thermal materials
• CPC Class Codes: G01J 5/10 using electric radiation detectors
• CPC Class Codes: G01J 5/20 using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices
• CPC Class Codes: G01K 17/20 across a radiating surface, combined with ascertainment of the heat transmission coefficient materials therefor G01K17/08
• CPC Class Codes: H01L 29/66992 controllable only by the variation of applied heat controllable by IR radiation H01L31/00; measuring quantity of heat G01K17/00
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A semiconductor device with an electric converter element on a diaphragm is provided, in which the diaphragm has an improved thermal shielding or blocking capability from a semiconductor substrate without lowering the mechanical strength of a leg of the diaphragm. The semiconductor device includes of a semiconductor substrate, a diaphragm mechanically connected to the substrate by a thermally-resistive leg, an electric converter element provided on the diaphragm, an electronic circuit formed on the substrate, and an electric path located on the leg for electrically connecting the electric converter element and the electronic circuit. The diaphragm is electrically insulated and thermally separated from the substrate. The electric converter element conducts a conversion between a physical quantity and an electric input/output signal. The electric path is made of a metal suicide to decrease its thermal conductivity without decreasing its electrical conductivity. The device is applicable to various sensors, generators, and actuators using heat.

Claims

1. A semiconductor device comprising:

a semiconductor substrate;

a diaphragm mechanically connected to said substrate by a thermally-resistive leg;

said diaphragm being electrically insulated and thermally separated from said substrate;

an electric converter element provided on said diaphragm;

said electric converter element conducting conversion between a physical quantity and an electric input/output signal;

an electronic circuit formed on said substrate;

an electric path located on said leg for electrically connecting said electric converter element and said electronic circuit; and

said electric path being made of metal silicide to decrease its thermal conductivity without decreasing its electrical conductivity,

wherein said electric converter element is made of a material selected from the group consisting of Ti_xO_y, Cu_uO_y, and Cu_xTi_yO_z, each of which is doped with an impurity having an action to decrease its electric resistivity.

2. A device as claimed in claim 1, wherein said doped impurity for Ti_xO_y is at least one selected from the group consisting of In, Sn, Nb, Ba, Sr, Pb, Zr, Cu, Pt, Co, Ru, and Ta, and their compounds.

3. A device as claimed in claim 1, wherein said doped impurity for Ti_xO_y is at least one selected from the group consisting of Ba and Sr, and their compounds.

4. A device as claimed in claim 1, wherein said doped impurity for Cu_xO_y is at least one selected from the group consisting of Ba, Sr, Pb, Zr, Ti, Pt, Co, Ru, and Ta, and their compounds.

5. A device as claimed in claim 1, wherein said doped impurity for Cu_xO_y is at least one selected from the group consisting of Ba and Sr, and their compounds.

6. A device as claimed in claim 1, wherein said doped impurity for Cu_xTi_yO_z is at least one selected from the group consisting of In, Sn, Nb, Ba, Sr, Pb, Zr, Cu, Pt, Co, Ru, and Ta, and their compounds.

7. A device as claimed in claim 1, wherein said doped impurity for Cu_xO_y is at least one selected from the group consisting of Ba and Sr, and their compounds.

8. A device as claimed in claim 1, wherein said diaphragm has a two-layer structure formed by a lower sublayer with a tensile stress and an upper sublayer with a compressive stress, said upper sublayer being stacked onto said lower sublayer;

and wherein said two-layer structure has a bimetal function to form a convex cross-section with respect to said substrate.

9. A device as claimed in claim 8, wherein said lower sublayer has an area ¾

times as much as said diaphragm.

10. A semiconductor device comprising:

a semiconductor substrate;

a diaphragm mechanically connected to said substrate by a thermally-resistive leg, said diaphragm being electrically insulated and thermally separated from said substrate;

an electric converter element provided on said diaphragm, said electric converter element converting between a physical quantity and an electric input/output signal;

an electronic circuit formed on said substrate; and

an electric path located on said leg for electrically connecting said electric converter element and said electronic circuit, said electric path consisting essentially of metal silicide to decrease its thermal conductivity without decreasing its electrical conductivity,

wherein said electric converter element has approximately a same electric resistance as that of said electric path on the leg.