Title :
Anomalies in MODFET´s with a low-temperature buffer
Author :
Lin, Barry Jia-fu ; Kocot, Christopher P. ; Mars, D.E. ; Jaeger, Rolf
Author_Institution :
Hewlett-Packard Lab., Palo Alto, CA, USA
fDate :
1/1/1990 12:00:00 AM
Abstract :
GaAs buffer layers grown by molecular-beam epitaxy (MBE) at low temperatures (200-300°C) have been successfully used to reduce sidegating in both MESFETs and MODFETs. There are, however, high concentrations of defects in the low-temperature (LT) buffers that adversely affect the high-frequency performance of precision analog and certain digital circuits. In unoptimized structures, nanosecond and microsecond transients are as large as 85 and 15% of the total voltage swing, respectively. These transients cause various detrimental effects in circuits. These effects are described. Their origin is attributed to the outdiffusion of defects from the LT buffer, and a method for optimizing the device structure for minimum sidegating and maximum high-frequency performance is presented
Keywords :
gallium arsenide; high electron mobility transistors; semiconductor device testing; transients; 200 to 300 degC; GaAs buffer; MBE; MESFETs; MODFETs; analog circuits; defect outdiffusion; defects; detrimental effects; device structure optimization; digital circuits; high-frequency performance; low-temperature buffer; microsecond transients; nanosecond transients; sidegating; unoptimized structures; voltage swing; Buffer layers; Digital circuits; Gallium arsenide; HEMTs; MESFETs; MODFET circuits; Molecular beam epitaxial growth; Nanostructures; Temperature; Voltage;
Journal_Title :
Electron Devices, IEEE Transactions on
