Semiconductor device having an improved air-bridge lead structure

• US 5,148,260 A
• Filed: 09/07/1990
• Issued: 09/15/1992
• Est. Priority Date: 09/07/1989
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Tomita, Kenichi, Inoue, Tomotoshi, Terada, Toshiyuki
• Primary Examiner(s): Hille, Rolf
• Assistant Examiner(s): CLARK, SHEILA V
• Application Number:
  US07/578,436
• Time in Patent Office: 739 Days
• Field of Search: 357/69, 357/68, 357/71, 357/67
• US Class Current: 257/762
• 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

A semiconductor device having an improved air-bridge lead structure is provided. The improved air-bridge lead structure has a higher mechanical strength and a lower electric resistance with a smaller electric capacitance.

Claims

1. A semiconductor device having an air-bridge lead structure comprising:

a semiconductor substrate having a surface;

a plurality of electrodes formed on the surface of said semiconductor substrate; and

an air-bridge lead electrically connected between said plural electrodes, said air-bridge lead having at least a first metal layer and a second metal layer, said first metal layer being integrally formed over an entire bottom length of said air-bridge lead and said second metal layer being formed on top of said first metal layer, said first metal layer having a Young'"'"'s modulus higher than that of said second metal layer, and said second metal layer having a specific electric resistance lower than that of said first metal layer.

2. The semiconductor device of claim 1, wherein said second metal layer has a cross-sectional area greater than that of said first metal layer.

3. The semiconductor device of claim 2, wherein said second metal layer includes a metal-plated layer, and said first metal layer includes a metal layer formed by use of an evaporation technique.

4. The semiconductor device of claim 1,

wherein said first metal layer includes a metal selected from W, Mo, Rh and Ru or a compound including at least one of W, Mo, Rh and Ru and a second metal layer including a metal selected from Au, Al and Cu.

5. The semiconductor device of claim 4, wherein said compounds include WAl, WSi₂, and MoSi₂.

6. A semiconductor device having an air-bridge lead structure comprising:

a semiconductor substrate having a surface;

a plurality of electrodes formed on the surface of said semiconductor substrate;

a first air-bridge lead layer connected between said plurality of electrodes;

a second air-bridge lead layer formed on said first air-bridge lead layer; and

said first air-bridge lead layer having a Young'"'"'s modulus higher than that of said second air-bridge lead layer, and said second air-bridge lead layer having a specific electric resistance lower than that of said first air-bridge lead layer, said first metal layer being integrally formed over an entire bottom length of said air-bridge lead and said second metal layer being formed on top of said first metal layer.

7. The semiconductor device of claim 6, wherein said second air-bridge lead layer has a cross-sectional area greater than that of said first air-bridge lead layer.

8. The semiconductor device of claim 6, wherein said first air-bridge lead layer includes a metal selected from W, Mo, Rh and Ru, or includes a compound including at least one of W, Mo, Rh and Ru, and said second air-bridge lead layer includes a metal selected from Au, Al and Cu.

9. The semiconductor device of claim 8, wherein said first air-bridge lead layer includes W, and said second air-bridge lead layer includes Au.

10. The semiconductor device of claim 8, wherein said compounds include WAl, WSiO₂, and MoSiO₂.