Title :
An all-implanted, self-aligned, GaAs JFET with a nonalloyed W/p+-GaAs ohmic gate contact
Author :
Zolper, J.C. ; Baca, A.G. ; Shul, R.J. ; Howard, A.J. ; Rieger, D.J. ; Sherwin, M.E. ; Lovejoy, M.L. ; Hjalmarson, H.P. ; Draper, B.L. ; Klem, J.F. ; Hietala, V.M.
Author_Institution :
Sandia Nat. Labs., Albuquerque, NM, USA
fDate :
7/1/1994 12:00:00 AM
Abstract :
We describe a self-aligned, refractory metal gate contact, enhancement mode, GaAs junction field effect transistor (JFET) where all impurity doping was done by ion implantation. Processing conditions are presented for realizing a high gate turn-on voltage (~1.0 V at 1 mA/mm of gate current) relative to GaAs MESFET´s. The high gate turn-on voltage is the result of optimizing the p+-gate implant and anneal to achieve a nonalloyed ohmic contact between the implanted p+-GaAs and the sputter deposited tungsten gate contact. Initial nominally 1.0 μm×50 μm n-JFET´s have a transconductance of 85 mS/mm and ft of 11.4 GHz
Keywords :
III-V semiconductors; gallium arsenide; ion implantation; junction gate field effect transistors; ohmic contacts; solid-state microwave devices; 1 V; 1 mum; 11.4 GHz; 50 mum; 85 mS/mm; GaAs; GaAs JFET; GaAs junction field effect transistor; all impurity doping; all-implanted; enhancement mode; gate current; high gate turn-on voltage; ion implantation; n-JFET´s; nonalloyed W/p+-GaAs ohmic gate contact; nonalloyed ohmic contact; p+-gate implant; processing conditions; refractory metal gate contact; self-aligned; sputter deposited tungsten gate contact; transconductance; Annealing; Doping; FETs; Gallium arsenide; Implants; Impurities; Ion implantation; MESFETs; Ohmic contacts; Voltage;
Journal_Title :
Electron Devices, IEEE Transactions on
