STUDY OF SURFACE REACTION IN MOCVD AND ALE USING IN AND P COMPOUNDS

InP是一种潜在的应用于高速和光学器件的材料。InP薄膜的制备通常采用分子束外延(MBE)、金属有机化学气相沉积(MOCVD)等方法，从实用角度来看，MOCVD是一种有效的制备InP薄膜的方法。由于薄膜是由复杂的金属有机化合物在半导体衬底上发生表面化学反应而形成的，因此需要对反应进行控制，以获得高质量的样品。因此，有必要阐明其反应机理。反应的第一步是吸附，随后在衬底表面发生分解反应，形成MOCVD薄膜。因此，研究金属有机物在衬底表面的吸附和分解是非常重要的。薄膜和衬底之间的界面由化合物的第一次吸收和随后的分解控制，强烈地影响Devi…的电学性质。我们用俄歇电子能谱(AES)、X射线能谱(PXS)、UPS、扫描隧道显微镜(STM)、TPD、HREELS、RHEED等方法研究了三乙基膦(TEI)、三甲基膦(MP)、三乙基膦(TEP)和三叔丁基膦(TBP)在Si(111)-7x7、Si(001)和GaP(001)表面上的吸附和分解。TMP优先吸附在Si(111)-7x7表面的中心吸附原子上。TeI和TEP在RT时以分子形式吸附在Si(001)和GaP(001)表面，并分解为乙烯和氢气，在表面分别留下In和P原子。在RT条件下，TBP在Si(001)和GaP(001)表面部分解离，分解为异丁烯和氢原子，P原子留在表面。Tei、TEP和TBP通过β-氢化物消除进行分解。TEI、TEP和TBP在GaP(001)面上的分解反应受氢气气氛的强烈影响，而在Si(001)面上影响不大，这是因为氢在GaP(001)面上发生解离吸收，而在Si(001)面上不发生。提出了TEI、TEP和TBP在Si(001)和GaP(001)表面的分解机理。较少

InP is a potential material for application to high speed and optical devices. Thin films of InP is usually fabricated by molecular beam epitaxy (MBE), metalorganic chemical vapor deposition (MOCVD), etc. From practical point of view, MOCVD is a useful method for fabrication of the film. Since the film is formed by surface chemical reaction of complex metalorganic compounds on semiconductor substrates, the reaction should be controlled to obtain good quality samples. Therefore, it is necessary to elucidate the reaction mechanism for the fabrication.The first step of the reaction is adsorption and subsequently decomposition and reaction occur on substrate surfaces, forming the films in MOCVD.Therefore, it is very important to study absorption and decomposition of the metalorganic compounds on the surfaces. Interface between the film and the substrates, which is controlled by the first absorption and following decomposition of the compounds, strongly affects electrical properties of devi … More ces.We have studied absorption and decomposition of triethylindium (TEI), trimethylphosphine (MP), triethylphosphine (TEP), and tertiarybutylphosphine (TBP), which have been used as precursors for MOCVD and ALE,on the Si (111)-7x7, Si (001), and GaP (001) surfaces using AES,PXS,UPS,STM,TPD,HREELS, RHEED.We obtain the following results.1. TMP absorbs preferably on centered adatom sites on a Si (111)-7x7 surface.2. TEI and TEP absorb molecularly on the Si (001) and GaP (001) surfaces at RT and are decomposed into ethylene and hydrogen, leaving In and P atoms on the surfaces, respectively.3. TBP is partially dissociated on the Si (001) and GaP (001) surfaces at RT and is decomposed into isobutylene and hydrogen, leaving P atoms on the surfaces.4. TEI,TEP,and TBP are decomposed through beta-hydride elimination.5. Decomposition reaction of TEI,TEP,and TBP on the GaP (001) surface are strongly affected with hydrogen ambience but not on the Si (001) surface, which is due to the fact that dissociative absorption of hydrogen occurs on GaP (001) but does not on Si (001).6. The decomposition mechanisms of TEI,TEP,and TBP on the Si (001) and GaP (001) surfaces were proposed. Less