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用氢等离子体腐蚀了半导体材料(如:GaAs、GaSb、InP、Si等)及其氧化物和氮化硅的表面。采用光谱椭圆仪、俄歇波谱仪和扫描电子显微镜(SEM)等综合分析技术,研究了刻蚀速率、表面组分和形态。实验证明:氢等离子体对于SiO_2上的硅和GaAs上的GaAs氧化物的选择刻蚀速率分别为30和2左右。还表明,经氢等离子体腐蚀的(曝露在空气中)GaAs表面上Ga/As的浓度比近似等于GaAs空气解理面上的Ga/As的浓度比。对于GaSb也得到了类似的结果。氢等离子体腐蚀过的InP表面呈现出偏析现象,即富In的表面结构。椭圆仪和电子显微镜测量的结果表明:半导体及其氧化物的腐蚀速率与被蚀物质的种类有关,对不同种类的化合物,腐蚀速率有几个数量级的差别。实验还证明:扫描椭圆仪可以用于表面腐蚀过程的监控。讨论了使用氢等离子体对材料表面制备的一些优缺点及在刻蚀方面的应用。
The surface of semiconductor materials (such as GaAs, GaSb, InP, Si, etc.) and their oxides and silicon nitride are etched with hydrogen plasma. The spectroscopic ellipsometry, Auger spectroscopy and scanning electron microscopy (SEM) were used to analyze the etching rate, surface composition and morphology. Experiments show that the selective etching rate of hydrogen plasma for silicon on SiO 2 and GaAs on GaAs is about 30 and about 2, respectively. It has also been shown that the Ga / As concentration ratio on the GaAs surface (exposed to the air) corroded by hydrogen plasma is approximately equal to the Ga / As concentration ratio on the GaAs air cleavage plane. Similar results have also been obtained for GaSb. Hydrogen plasma etched InP surface presents the phenomenon of segregation, that is rich in In surface structure. The results of ellipsometry and electron microscopy show that the corrosion rates of semiconductors and their oxides are related to the types of materials being etched, and that the corrosion rates differ by several orders of magnitude for different kinds of compounds. Experiments also prove that the scanning ellipsometer can be used to monitor the surface corrosion process. Some advantages and disadvantages of using hydrogen plasma to prepare the surface of the material and its application in etching are discussed.