Title :
A new fabrication technology for AlGaAs/GaAs HEMT LSIs using InGaAs nonalloyed ohmic contacts
Author :
Kuroda, Shigeru ; Harada, Naoki ; Katakami, Teruhiko ; Mimura, Takashi ; Abe, Masayuki
Author_Institution :
Fujitsu Lab. Ltd., Atsugi, Japan
fDate :
10/1/1989 12:00:00 AM
Abstract :
The authors studied the nonalloyed ohmic characteristics of HEMTs (high electron mobility transistors). At high integration levels, nonalloyed ohmic contacts were found to have two advantages: an extremely short ohmic length with low parasitic source series resistance and direct connection between the source/drain and gate with the same metal. The propagation delay in a ring oscillator with a single-metal source/drain and gate formed simultaneously was 37 ps/gate (L g=0.9 μm). The very short ohmic metal contacts and just three contact holes made it possible to reduce the memory cell area greatly. The cell is 21.5×21.5 μm2, one of the smallest ever reported for a GaAs-based static RAM. Using smaller load HEMTs or resistor loads in the memory cell, combined with nonalloyed ohmic technology with quarter- or subquarter-micrometer-gate HEMTs it is possible to fabricate a very-high-speed LSI such as a 64-kb static RAM with a reasonable chip size
Keywords :
III-V semiconductors; VLSI; aluminium compounds; field effect integrated circuits; gallium arsenide; indium compounds; integrated circuit technology; ohmic contacts; random-access storage; 0.25 micron; 0.5 micron; 37 ps; 64 kbit; AlGaAs-GaAs; HEMT LSI; InGaAs nonalloyed ohmic contacts; fabrication technology; high integration levels; memory cell area; parasitic source series resistance; propagation delay; ring oscillator; short ohmic length; single-metal source/drain; static RAM; very-high-speed LSI; Contact resistance; Fabrication; Gallium arsenide; HEMTs; Indium gallium arsenide; MODFETs; Ohmic contacts; Propagation delay; Random access memory; Read-write memory;
Journal_Title :
Electron Devices, IEEE Transactions on
