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研究了在MBE系统中 ,GaAs( 0 0 1 )表面的氮化过程。GaAs( 0 0 1 )表面直接和间接地暴露在等离子体激发的N2 气流下。两种氮化过程显示了完全不同的表面氮化结果。在打开N2 发生器挡板的情况下 ,氮化导致GaAs( 0 0 1 )表面损伤 ,并且形成多晶结构。当增加N2 气压时 ,损伤变得更严重。但是 ,在关闭N2 发生器挡板的情况下 ,在 5 0 0℃下 ,经过氮化将观察到 ( 3× 3)再构的RHEED花样 ,表面仍保持原子级的平整度。上述结果表明 ,不开N2 发生器挡板 ,低温 ( 5 0 0℃下 )氮化将在GaN外延生长之前形成平整的薄层c GaN。
The nitridation of GaAs (0 0 1) surface in MBE system was studied. The GaAs (0 0 1) surface is directly and indirectly exposed to plasma-excited N 2 gas flow. Both nitriding processes show quite different surface nitriding results. Nitriding causes the surface of GaAs (001) to be damaged and a polycrystalline structure is formed with the N2 generator baffle open. When N2 pressure is increased, the damage becomes more severe. However, with the N2 generator baffle closed, (3x3) reconfigured RHEED patterns were observed after nitriding at 500 ° C and the surface remained atomically flat. The above results show that without the N2 generator baffle, a low temperature (at 500C) nitridation will form a flat thin layer of cGaN prior to GaN epitaxial growth.