Process for manufacturing integrated devices comprising microstructures and associated suspended electrical interconnections

• US 6,469,330 B1
• Filed: 10/20/1999
• Issued: 10/22/2002
• Est. Priority Date: 10/21/1998
• Status: Expired due to Term

• Current Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Inventors: Mastromatteo, Ubaldo, Vigna, Benedetto
• Primary Examiner(s): Chaudhuri, Olik
• Assistant Examiner(s): Mai, Anh Duy
• Application Number:
  US09/422,049
• Time in Patent Office: 1,098 Days
• Field of Search: 438/48-54, 438/411, 438/421, 438/619, 257/522, 257/254
• US Class Current: 257/254
• CPC Class Codes: H01L 23/4821 Bridge structure with air gap
• CPC Class Codes: H01L 23/5221 Crossover interconnections
• 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

An integrated device comprises an epitaxial layer forming a first and a second region separated by at least one air gap. The first region forms, for example, a suspended mass of an accelerometer. A bridge element extends on the air gap and has a suspended electrical connection line electrically connecting the first and the second region and a protective structure of etch-resistant material, which surrounds the electrical connection line on all sides. The protective structure is formed by a lower portion of silicon nitride and an upper portion of silicon carbide, the silicon carbide surrounding the electrical connection line at the upper and lateral sides.

Claims

1. An integrated device, comprising:

a semiconductor body having first and second regions separated by an air gap;

a conductive line extending over the air gap, the conductive line electrically connecting the first and second regions; and

a protective structure at least partially surrounding the conductive line wherein the protective structure includes an upper protective region comprising silicon carbide.

2. An integrated device, comprising:

a semiconductor body having first and second regions separated by an air gap;

a conductive line extending over the air gap, the conductive line electrically connecting the first and second regions; and

a protective structure at least partially surrounding the conductive line wherein the protective structure further comprises a lower protective region comprising a silicon nitride portion.

3. An integrated device, comprising:

a semiconductor body having first and second regions separated by an air gap;

a conductive line extending over the air gap, the conductive line electrically connecting the first and second regions;

a protective structure at least partially surrounding the conductive line; and

an insulating region disposed beneath the conduction line and wherein the protective structure includes a lower protective region disposed beneath the insulating region.

4. An integrated device, comprising:

a semiconductor material body including a first and a second region adjacent to and separated by an air gap;

a bridge element including a suspended electrical connection line extending between said first and said second regions on said air gap and electrically joining said first and second regions; and

a protective structure of etch-resistant material, surrounding said electrical connection line, said protective structure including a lower protective region and an upper protective region both of electrically insulating material and surrounding said electrical connection line, said electrical connection line having a first and a second end in direct electrical connection with said first and said second regions, respectively, said lower protective region having a silicon nitride portion, said upper protective region having a silicon carbide portion.

5. An integrated device, comprising:

a semiconductor material body housing a first and a second region separated by at least one air gap;

a bridge element including a suspended electrical connection line extending between said first and said second regions on said air gap and electrically joining said first and second regions;

a protective structure of etch-resistant material, surrounding said electrical connection line, said protective structure comprising a lower protective region and an upper protective region both of electrically insulating material and surrounding said electrical connection line, said lower protective region comprising a silicon nitride portion, said electrical connection line having a first and a second end in direct electrical connection with said first and said second regions, respectively; and

a region of silicon oxide disposed between said silicon nitride portion and said electrical connection line.