R.H. Hopkins

Learn More
The effects of various metallic impurities, both singly and in combinations, on the performance of silicon solar cells have been studied. Czochralski crystals were grown with controlled additions of secondary impurities. The primary dopants were boron and phosphorus while the secondaires were: A1, B, C, Ca, Co, Cr, Cu, Fe, Mg, Mn, Mo, Nb, P, Pd, Ta, Ti, V,(More)
State-of-the art SiC MESFET's showing a record high f/sub max/ of 26 GHz and RF gain of 8.5 dB at 10 GHz are described in this paper. These results were obtained by using high-resistivity SiC substrates for the first time to minimize substrate parasitics. The fabrication and characterization of these devices are discussed.<<ETX>>
Silicon Carbide (SiC) is an emerging semiconductor material which has been widely predicted to be superior to both Si and GaAs in the areas of microwave power devices, power electronic switching devices, high temperature analog and digital electronics, non-volatile memories and UV sensors. This paper presents an overview of SiC electronic properties,(More)
By coupling the results of electrical measurements, such as spectral response, lighted and dark I-V determinations, and deep-level-transient spectroscopy with optical and laser scan photomicroscopy, we have evaluated the effects of grain boundaries and impurities on silicon solar cells. Titanium which produces two deep levels,<tex>E_{v} +(More)
We report for the first time the development of state-of-the-art SiC MESFETs on high-resistivity 4H-SiC substrates. 0.5 /spl mu/m gate MESFETs in this material show a new record high f/sub max/ of 42 GHz and RF gain of 5.1 dB at 20 GHz. These devices also show simultaneously high drain current, and gate-drain breakdown voltage of 500 mA/mm, and 100 V,(More)
  • 1