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 super-low-noise HEMT with a mushroom-shaped 0.25- mu m 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 high reproducibility and controllability of resist profiles. The gate resistance was extremely reduced by providing 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 :
electron device noise; high electron mobility transistors; ion beam lithography; solid-state microwave devices; 0.68 dB; 0.83 dB; 12 GHz; 18 GHz; 7.7 dB; 9.7 dB; Be/sup 2+/; Si/sup 2+/; T-shaped resist profiles; focused ion beam lithography; gate resistance; high electron mobility transistor; microwave device; minimum noise figure; mushroom gate; super-low-noise HEMT; Collision mitigation; Etching; Fabrication; HEMTs; Ion beams; Lithography; MODFETs; Molecular beam epitaxial growth; Resists; Substrates;
Conference_Titel :
Microwave and Millimeter-Wave Monolithic Circuits Symposium, 1988. Digest of Papers., IEEE 1988
Conference_Location :
New York, NY, USA
DOI :
10.1109/MCS.1988.197309
