Abstract
Direct sulfurization of GaAs surfaces by treatment with P2S 5/(NH4)2SX was employed to yield gate insulating layers for a depletion-type recessed gate GaAs metal-insulator-semiconductor-like pseudomorphic high-electron mobility transistor (MIS-like pHEMT). The novel P2S5/(NH 4)2SX-treated GaAs provided a lower surface roughness and more Ga-S bonds than the traditional (NH4) 2SX-only sulfurized GaAs; these bonds improved device uniformity and reduced the surface states that are induced by native Ga-O bonds. The diffusion of S atoms from P2S5/(NH4) 2SX sulfurization simultaneously suppressed the drain-to-source current (Ids). The Schottky gate reverse leakage current was suppressed, resulting in a higher breakdown voltage, when this sulfurized GaAs insulator was used. Based on the dc and 1 νs pulse I-V measurement results, P2S5/(NH4) 2SX-treated GaAs MIS-like pHEMTs exhibited identical Ids trends; however, conventional NH4OH-treated pHEMT exhibited an obvious decline in current upon pulse measurement because of the higher surface traps. These results were consistent with the characterization of this insulating film.
Original language | English |
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Article number | 035029 |
Journal | Semiconductor Science and Technology |
Volume | 23 |
Issue number | 3 |
DOIs | |
State | Published - 01 03 2008 |