Rao V. Mulpuri

Research Activities

Completed Research

Research has been done on the following topics:

  1. Spin-on sources for dopant diffusion in silicon: Boron and arsenic spin-on sources were developed for making silicon devices.

  2. Liquid phase epitaxial growth and characterization of In0.53Ga0.47As (InGaAs hereafter). Material with electron mobility as high as 10,000 cm2/V-s has been grown. Various background impurities have been identified by photoluminescence measurements.

  3. Photoconductive and metal semiconductor metal (MSM) InGaAs photodetector fabrication and characterization for 1.2 - 1.6 Ám application. Detectors with dark current as low as nA range have been made.

  4. Ion implantation of various elements (Si, S, Ge, Be, Mg, S, Fe, Cr, Co, V, H, He, Ar, B, Al, Ga, As, Sb, N, Ne, and Ti) into III V compound semiconductors like GaAs, InP, InGaAs, InSb, GaSb, InAlAs and GaN and group IV compounds like SiC and GexSi1-x have been performed. These implants were performed in the ion energy range 10 keV - 20 MeV. The annealed material has been characterized by various techniques like SIMS, Hall, RBS, X ray rocking, and Polaron C-V profiling techniques. These implants are useful for making optoelectronic and microwave devices.

  5. Fabrication and characterization of vertical GaAs and InP PIN diodes for high power microwave switching application. Devices with breakdown voltage as high as 120 V have been made.

Current Research

  1. Electrical, optical, and structural characterization of as-grown and ion implanted compound semiconductors, like SiC and GaN

  2. Fabrication and characterization of high-power and high-temperature devices(rectifier diodes, MESFETs, MISFETs, DMOSFETs, etc. ) using SiC and GaN.

  3. High performance ohmic contacts to GaN.

  4. Rapid microwave annealing of ion-implanted GaN and SiC

  5. Micro-fluidic cells for biological sample analysis and micro-arrays for proteomics.

  6. Fabrication of CdHgTe/Si infrared focal plane arrays