Specific gravity difference method in liquid phase epitaxial growth of semiconductor

比重差法，又称溜溜球溶质供给法，是一种有效的硅及合金晶体厚层生长方法。我们对连续两年左右的温度起伏引起的生长溶液中溶质的输运现象进行了生长实验和数值分析.数值分析：以下内容已明确。由溶质溶解引起的生长溶液中密度的空间调制引起强对流。这种对流增强了位于溶液下部的源物质的溶解，并在上部形成平流层。这些过程大约需要10分钟。这些数据可以用于改善生长条件。硅生长：研究了生长层与高阻非掺杂衬底之间的晶格匹配条件。X射线衍射分析表明，在铟生长溶剂中加入适量的锡可以实现重掺磷生长层的晶格匹配.合金生长：（1）绘制了Ge-Si合金生长相图。在<0.2><0.8>锡和铟溶剂中可以生长出厚度为1 mm的Ge_ Si_2层。（2）在1000 ℃的高温下，在GaAs衬底上可以在准二元条件下生长GaInAs合金层。（3）研究了GaP衬底上生长Galvanic合金的初始条件。在<0.8><0.2>生长溶液与衬底之间建立了近平衡条件后，通过缓慢冷却溶液，可以直接在GaP上生长Ga_ In_ P层。这种合金的厚层生长将通过后续的溜溜球工艺来实现，我们认为这种生长方法将成为未来电子学的重要技术之一。

The specific gravity difference method, named yo-yo solute feedingmethod, is effective on thick layer growth of silicon and alloy crystals. We have carried out the growth experiments and the numerical analysis for the transport phenomena of the soulte in the growth solution caursed by the yo-yo temperature cycles extending oger two years.1. Numerical analysis: Followings were made clear. Spatial modulation in density in the growth solution resulted from the dissolution of the soulte induces strong convection. This convection enhances the dissolution of the source material set at lower portion of the solution, and stratosphere is formed at upper portion. These processes require about 10 min. The data can be available for improvement of the growth conditions.2. Silicon growth: Lattice-matching condition between grown layer and high resistive non-doped substrate was investigated. X-ray measurements revealed the lattice-matching of heavily phosphorus-doped grown layer could be acheived by adding a suigable amount of tin into indium growth solvent.3. Alloy growth: (1)Phase diagrams concerning the growth of Ge-Si were completed. Ge_<0.2>Si_<0.8> layer of 1 mm in thickness could be grown from tin and indium solvents. (2)GalnAs alloy layer could be grown on GaAs substrate under near pseudo-binary condition at nigh temperature of 1000 C. (3)The initial growth conditions of GalnP alloy on GaP substrate were investigated. Ga_<0.8>In_<0.2>P layer could be directly grown on GaP by cooling the solution very slowly after establishing near-equilibrium condition between growth solution and substrate. Thick layer growth of this alloy will be realized by subsequent yo-yo procedures.We think this growth method will be developed as one of the important-techniques in fufure electronics.