Papers Published

1. Mishra, U.K. and Brown, A.S. and Jelloian, L.M. and Melendes, M.A. and Thompson, M. and Rosenbaum, S.E. and Larson, L.E., Impact of buffer layer design on the performance of AlInAs-GaInAs HEMT's, IEEE Transactions on Electron Devices, vol. 36 no. 11 pt 1 (1989), pp. 2616 - [16.43731] .
   (last updated on 2007/04/14)

   Abstract:
   Summary form only given. The authors report a study of the impact of buffer layer design on the characteristics of Al_0.48In_0.52As-Ga_0.47In_0.53As HEMTs (high-electron-mobility transistors). The aim of the study is to understand and correct the problem of high output conductance observed in devices with a high transconductance. Devices with 1.0-μm gate lengths were fabricated using modulation-doped Al_0.48In_0.52As-Ga_0.47In_0.53As epitaxial layes which had sheet charge densities between 3 × 10¹² and 3.5 × 10¹² cm^-2 and mobilities at 300 K between 9000 and 10,000 cm V^-1 S^-1. The different buffer layer designs used were: 1) a standard undoped Al_0.48In_0.52As buffer 250-nm-thick; 2) an Al_0.48In_0.52As buffer with a 20-angstrom thick highly doped p-type region 50 angstrom below the channel; 3) A Ga_0.47In_0.53As buffer with a 20-angstrom-thick highly doped p-type region below the channel; and 4) a low-temperature AlInAs buffer layer. The device with the low-temperature AlInAs had the best output characteristics, signifying that it was the best mode of confining electrons in the channel.

   Keywords:
   Electrons--Transport Properties;Semiconductor Materials--Doping;