硫化铵钝化锑化镓表面的化学与电学性质研究

本文利用X射线光电子能谱（XPS），飞行时间二次离子质谱（TOF-SIMS）和电流-电压特性（I-V）对不同硫化铵溶液（(NH4)2S）钝化后的锑化镓（GaSb）表面化学性质进行了研究。通过对比,发现中性(NH4)2S S溶液对GaSb表面的钝化能力要优于纯(NH4)2S溶液和碱性(NH4)2S S溶液。碱性(NH4)2S S溶液在有效去除GaSb表面氧化物的同时形成硫化物产物以改善器件性能。TOF-SIMS测试结果从另一方面证实纯(NH4)2S溶液钝化也会形成硫化物产物，但该产物在纯(NH4)2S溶液中是可溶的，以至于很难稳定地存在。3D光学轮廓仪测试结果显示中性(NH4)2S S溶液钝化的GaSb表面具有最低的粗糙度。I-V测试结果表明中性(NH4)2S S溶液钝化能显著提高GaSb基肖特基二极管的电学性能。综上所述，中性(NH4)2S S溶液的钝化效果在改进GaSb表面性质方面具有最优的结果。

Chemical and electrical properties of (NH4)2S passivated GaSb surface

The surface chemical properties of gallium antimonide (GaSb) after ammonium sulfide ((NH₄)₂S) solution passivation have been studied by X-ray photoelectron spectroscopy (XPS), time of flight secondary ion mass spectroscopy (TOF-SIMS) and I-V measurement. An advantage of neutral (NH₄)₂S + S solution over pure (NH₄)₂S solution and alkaline (NH₄)₂S + S solution has been found in the ability to passivate the GaSb surface by contrast and comparison. It has been found that alkaline (NH₄)₂S + S solution passivation effectively removes oxides of the GaSb surface and forms sulfide products to improve device performance. TOF-SIMS complementally demonstrates that pure (NH₄)₂S passivation did form sulfide products, which are too soluble to really exist. The lowest roughness determined using a 3D optical profilometer and the highest improved SBD quality proved that neutral (NH₄)₂S + S solution passivation worked much better in improving the surface properties of GaSb.