1. W.v. Muench and I. Pfaffeneder: J. Appl. Phys., 48 (1977) 4833.
2. W.v. Muench and E. Pettenpaul: J. Appl. Phys., 48 (1977) 4823.
3. K. Koga, T. Tanaka and T. Tanaka Ext. Abstr. 17th Conf. Solid State Devices and Materials (Business Center for Academic Societies, Japan, Tokyo, 1985) p.249.
4. H. Matsunami, S. Nishino and H. Ono: IEEE Trans. Electron Devices, ED-28 (1981) 1235.
5. S. Nishino, H. Suhara and H. Matsunami: Ext. Abstr. 16th Conf. Solid State Devices and Materials (Business Center for Academic Societies, Japan, Tokyo, 1983) p.317.