Title :
A high electron mobility transistor with a mushroom gate fabricated by focused ion beam lithography
Author :
Sasaki, Y. ; Nagahama, K. ; Hosono, K. ; Katoh, T. ; Komaru, M.
Author_Institution :
Mitsubishi Electr. Corp., Itami, Japan
Abstract :
A superlow-noise HEMT (high-electron-mobility transistor) with a mushroom-shaped quarter-micrometer gate was fabricated using focused ion-beam lithography. The mixed exposure of Be/sup ++/ and Si/sup ++/ focused ion beams was used to form T-shaped resist profiles. This method has the advantages of a high reproducibility and controllability of resist profiles. The gate resistance was extremely reduced by producing this mushroom-shaped gate. As a result, the fabricated HEMT showed a minimum noise figure (NF/sub min/) of 0.68 dB, with an associated gain (G/sub a/) of 9.7 dB at 12 GHz. This device also showed an NF/sub min/ of 0.83 dB with a G/sub a/ of 7.7 dB at 18 GHz.<>
Keywords :
high electron mobility transistors; ion beam lithography; 0.68 dB; 0.83 dB; 12 GHz; 18 GHz; 7.7 dB; 9.7 dB; T-shaped resist profiles; controllability; focused ion beam lithography; high electron mobility transistor; minimum noise figure; mushroom gate; quarter-micrometer gate; reproducibility; resist profiles; superlow-noise HEMT; Etching; Fabrication; HEMTs; Ion beams; Lithography; MODFETs; Molecular beam epitaxial growth; Optical scattering; Resists; Substrates;
Conference_Titel :
Microwave Symposium Digest, 1988., IEEE MTT-S International
Conference_Location :
New York, NY, USA
DOI :
10.1109/MWSYM.1988.22024
