AlN and AlGaN growth using low-pressure metalorganic chemical vapor deposition

In AlGaN growth using low-pressure metalorganic chemical vapor deposition t he TMA-Bow-rate dependence and reactor-pressure dependence on the Al conten t were investigated. We found that the reduction of partial pressure of TMA is effective in preventing the reduction of the Al content. To apply AlN a nd AlGaN films to devices, we fabricated an insulated gate heterostructure field effect transistor (IG-HFET). The AFM image of 4 nm-thick AIN on GaN s hows a rough surface composed of approximately 500 nm-size grains. The grai n boundary may be the origin of the leakage current between gate and drain during the operation of the IG-HFET. Nevertheless, the device can operate w ith transconductance g(m) of 235 mS mm(-1) for L-g = 1.4 mu m. (C) 1998 Els evier Science B.V. All rights reserved.