Title :
A self-aligned gate lightly doped drain (Al, Ga)As/GaAs MODFET
Author :
Akinwande, A.I. ; Tan, K.L. ; Chen, C.H. ; Vold, P.J.
Author_Institution :
Honeywell Phys. Sci. Center, Bloomington, MN, USA
fDate :
6/1/1988 12:00:00 AM
Abstract :
An asymmetrical lightly doped drain (LDD) (Al, Ga)As/GaAs modulation-doped FET (MODFET) structure with high drain-to-source and drain-to-gate breakdown voltages was fabricated. The LDD structure has a self-aligned lightly doped n/sup -/ region between the channel and a heavily doped n/sup +/ region at the drain, to reduce the electric field and impact ionization. The length of the lightly doped n/sup -/ region on the drain side was varied from 0 to 1 mu m. Drain-to-source breakdown voltage BV/sub ds/ improved from 4.6 to >10 V while the transconductance g/sub m/ remained unchanged. The drain-to-gate reverse breakdown voltage BV/sub dg/ increased from approximately=7 to >20 V. The two breakdown mechanisms are believed to be independent. The LDD MODFET should find widespread application in circuits requiring high breakdown voltage such as high-speed analog-to-digital converters (ADCs) and microwave power amplifiers.<>
Keywords :
III-V semiconductors; aluminium compounds; gallium arsenide; high electron mobility transistors; semiconductor technology; solid-state microwave devices; 10 V; 20 V; AlGaAs-GaAs; HEMT; LDD MODFET; asymmetrical structure; breakdown mechanisms; drain to source breakdown voltage; drain-to-gate reverse breakdown voltage; high breakdown voltage; lightly doped drain; self-aligned gate; semiconductors; transconductance; Analog-digital conversion; Breakdown voltage; Epitaxial layers; FETs; Gallium arsenide; HEMTs; Impact ionization; MODFET circuits; Microwave circuits; Transconductance;
Journal_Title :
Electron Device Letters, IEEE
