Title :
Impact of interface impurities on heterostructure field-effect transistors
Author :
Reynolds, C.L., Jr. ; Vuong, T. Hong Ha ; Peticolas, Larry J.
Author_Institution :
AT&T Bell Labs., Reading, PA, USA
fDate :
11/1/1992 12:00:00 AM
Abstract :
The influence of C and Si impurities at the substrate/epitaxy interface on the threshold voltage of GaAs/AlGaAs selectively doped heterostructure transistors has been investigated both experimentally and theoretically using a one-dimensional simulation. The presence of C raises the conduction band relative to the Fermi level and reduces the electron density in the channel. This results in a positive shift of the depletion-mode (DFET) threshold voltage as the interfacial C concentration increases. For low C concentrations the DFET threshold voltage decreases with increasing Si at the interface. The impact of interfacial C and Si is small on the enhancement-mode (EFET) threshold voltage
Keywords :
III-V semiconductors; aluminium compounds; carbon; gallium arsenide; high electron mobility transistors; semiconductor doping; silicon; DFET; EFET; Fermi level; GaAs-AlGaAs; GaAs:C; GaAs:Si; HEMT; SDHT; conduction band; depletion mode FET; electron density; enhancement mode FET; heterostructure field-effect transistors; interface impurities; selectively doped heterostructure transistors; semiconductors; substrate/epitaxy interface; threshold voltage shift; Contamination; Epitaxial growth; FETs; Gallium arsenide; HEMTs; Impurities; MODFETs; Molecular beam epitaxial growth; Substrates; Threshold voltage;
Journal_Title :
Electron Devices, IEEE Transactions on
