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The chemical nature of the encapsulant-indium phosphide interface before and after rapid thermal annealing (RTA) was investigated using X-ray photoelectron spectroscopy (XPS). Rapid thermal annealing was investigated for ion implanted indium phosphide (InP) metal-insulator-semiconductor field-effect transistor (MISFET) fabrication. Silicon nitride films were used to encapsulate InP for RTA at 700 to 800 C for 10 to 60 sec in pure N2 or H2. The chemical nature of the encapsulant-InP interactions was examined using a sequence of high-resolution X-ray photoelectron spectra at four depths through the interfacial region for the In 3d5/2, P 2p, N 1s, Si 2p, and 0 1s peaks. The possible interfacial native oxides observed from the In 3d5/2 peak were In-O-H compounds such as In(OH)3, In0-0H, or In02. No InPO4 was observed in the P 2p peak. The N 1s peak had a component consistent with N-H or N-N bonding in which the area decreased by 42 to 100% after RTA. Changes in the width of the silicon oxy-nitride component of the Si 2p and 0 1s peaks indicated changes in the composition of the interfacial oxides after RTA. InP MISFET's were made on 2 inch semi-insulating wafers using a 150 keV, 4x1013 cm-2 silicon implant for the source and drain regions. The implanted substrates were rapid thermal annealed at 700 C for 30 sec in N2 or H2. The MISFET's were fabricated with a phosphorus oxide/silicon dioxide gate insulator which had a phosphorus oxide region at the insulator-InP interface. The gate insulator had a breakdown field of 2.5x10 6 V/cm and a resistivity of 1x10 15 Ω-cm. The InP MISFET's had transconductance of 27 mS/mm, channel electron mobility of 1200 cm2V-lsec-1, and drain current drift of 7%.
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