AUGER ELECTRON AND X-RAY PHOTOELECTRON SPECTROSCOPIC INVESTIGATION OF ENCAPSULATED ANNEALING OF III-V COMPOUND SEMICONDUCTORS (PLASMA DEPOSITION, SILICON-NITRIDE, ION IMPLANTATION)

Auger electron spectroscopy and x-ray photoelectron spectroscopy have been applied to the investigation of the encapsulated annealing of ion implanted gallium arsenide (GaAs) and indium phosphide (InP). In addition, infrared spectroscopic and capacitance-voltage and current-voltage measurements were used for further characterization.;The encapsulating capability of silicon nitride deposited with 30 KHz rf excitation was studied as a function of temperature, pressure, power, nitrogen to silane ratio, and flow rate. The silicon, nitrogen and hydrogen content of the films was determined by Auger electron spectroscopy and infrared spectroscopy. Most of the films had a silicon to nitrogen ratio between 0.71 and 0.76 and a hydrogen concentration between 10% and 19%. The most common failure mechanism was blistering during the anneal due to excessive compressive stress. GaAs substrates implanted with silicon at 100 KeV to a dose of 5 x 10('12) cm('-2) were annealed at 800(DEGREES)C for 7 min. The peak electron concentration, determined from capacitance-voltage measurements, was 1.7 x 10('17) cm('-3) at 0.1 (mu)m with 60% activation.;Silicon nitride that was a plasma deposited with 13.56 MHz excitation did not blister upon annealing. GaAs samples implanted with a dose of 5 x 10('12)cm('-2) at 100 KeV had 60% activation. Samples implanted with a dose of 3 x 10('12)cm('-2) at 150 KeV had a peak electron concentration of 9.6 x 10('16)cm('-3) at 0.12 (mu)m with 70% activation. InP samples, also encapsulated at 13.56 MHz, were annealed at 700(DEGREES)C for 10 min. Samples implanted with a dose of 5 x 10('12)cm('-2) at 100 KeV and 3 x 10('12)cm('-2) at 150 KeV had activations of about 60%. No chemical interaction between the silicon nitride and InP was observed by x-ray photoelectron spectroscopy.;The encapsulated annealing procedure was utilized in the fabrication of GaAs Schottky-gate field-effect-transistors which were characterized with current-voltage measurements. A 3 (mu)m gate length transistor had a transconductance of 30 mS/mm.;Auger electron spectroscopic studies showed that the silicon nitride encapsulant/substrate interface was contaminated with fluorine during plasma deposition. A modified deposition procedure eliminated the fluorine contamination. Plasma exposure did not damage the GaAs or InP surface. X-ray photoelectron spectroscopy was employed to study the surface of GaAs treated by degreasing and with HCl, HF and NH(,4)OH solutions. An HCl clean left the least oxygen on the surface.