Elementary Processes of Surface Photodissociation by Time-Resolved Photoelectron Spectroscopic and Laser Spectroscopic Techniques

我们利用激光技术和光电子光谱技术研究了卤素和有机金属化合物在绝缘体、金属和半导体上的热解和光解离解。在100k的激光照射下，在193nm或351nm处对硅晶片上的多层Cl_3或CH_3Cl进行激光照射，可使这些分子光解离并形成光刻产物。测定了光刻碎片（Cl, CH_3）和蚀刻产物（SiCl, SiCl_2）的动能分布。用x射线光电子能谱研究了三甲基镓（TMGa）和三甲基lindium （TMIn）在80 ~ 670 K不同温度下在Si、Au和Al基体上的热解解离。结果表明，Si（111）上的TMGa和TMIn在200 K时解离成Ga、In和CH_3， CH_3在较高温度下解离成C、CH和CH_2。在入射波长为193 nm和226 nm的情况下，在Si、GaAs或Au上观察到TMGa和TMIn单层光解作用；被吸收分子的直接吸收发生在这个波长。在355nm时，不会发生光解。用飞行时间质谱法研究了有机金属化合物（四甲基锡、三甲基镓、三甲基lindium和二甲基锌）在四赫兹衬底上100k吸收的光解动力学，主要检测CH_3光碎片。

We have studied pyrolytic and photolytic dissociation of halogen and organometallic compounds on insulators, metals, and semiconductors with laser techniques and photoelectron spectroscopic techniques.Laser irradiation at 193 or 351 nm of a multilayer of Cl_3 of CH_3Cl on an Si wafer at 100 K leads to both photodissociation of these molecules and formation of photoetchig products. The kinetic energy distributions of photofragments (Cl, CH_3) and etching products (SiCl, SiCl_2) were measured.Pyrolytic dissociation of trimethylgallium (TMGa) and trimethylindium (TMIn) on Si, Au, and Al substrates was studied at various temperatures from 80 to 670 K by x-ray photoelectron spectroscopy. The results indicate that TMGa and TMIn on Si (111) dissociates into Ga, In, and CH_3 on the substrateeven at 200 K and CH_3 surther dissociates into C, CH, and CH_2 at higher temperatures. Photodissociation of a monolayer of TMGa and TMIn on Si, GaAs, or Au is observed with an incident wavelength of 193 and 226 nm ; direct absorption by the absorbed molecules occurs at this wavelength. A 355 nm, photodissociation does not occur.The photodissociation dynamics of organometallic compounds (tetramethyltin, trimethylgallium, trimethylindium and dimethylzinc) absorbed on a quatrz substrate at 100 K have been studied by time-of-flight massspectrometry, detecting mainly CH_3 photofragments.