Short pulse Supersonic Beam Epitaxy

短脉冲超声束外延技术是为克服传统晶体生长技术的局限性而发展起来的一种新的晶体生长技术，它实现了对晶体生长的超精细控制。众所周知，外延晶体生长的基本过程基本上分为四个过程，即源气进气、迁移、分解和脱附。然而，这些过程中的每一个过程在常规外延技术中都不能控制，而每个过程的控制是外延生长超精细控制的关键。在短脉冲超声束外延中，源气具有很高的动能，只有几个eV，这比常规晶体生长中的源气动能高出约30倍。这种源气的高动能使得增强和控制源气的表面迁移、分解和脱附成为可能，这在传统技术中是不可能的。在本研究中，我们成功地(1)开发了短脉冲超声束外延系统和外延生长，(2)通过引入具有高动能的源气来提高表面上三甲基镓的分解速度，使碳进入外延层的数量大大减少。(3)超精细控制外延生长速率为0.1monolayr/Pulse。

A new technique of crystal growth, Short pulse Supersonic Beam Epitaxy, has been developed for overcoming the limitation of conventional crystal growth technique, by which ultra fine control of crystal growth is realized.It is well-known that fundamental processes in epitaxial crystal growth are separated basically into four processes, that is, feeding of source gas, the migration, the decomposition and the desorption.However, each of these processes can not be controlled in conventional epitaxial technology, though control of each process is essential for the ultra fine control of epitaxial growth.In the short pulse supersonic beam epitaxy, the source gas has high kinetic energy of a few eV,which is about 30 times higher than the kinetic energy of source gas in conventional crystal growth. This high kinetic energy of source gas makes it possible to enhance and control the surface migration of source gas, the decomposition and the desorption which was impossible in conventional technique.In this study we succeeded in(1) the development of short pulse supersonic beam epitaxy system and the epitaxial growth of GaAs,(2) large reduction of carbon incorporation into epitaxial layr by enhancing the decomposition velocity of Trimethyl Ga on the surface by introducing source gas having high kinetic energy.(3) ultra fine control of epitaxial growth rate of 0.1 monolayr/pulse.