Photodissociation Dynamics on Surface Probed by Vacuum uv Laser.

用X射线和紫外光电子能谱技术研究了三甲基镓在Si、Au和Al衬底上的热解和光解。在Si（111）衬底上，通过热分解沉积了金属镓和CH_n自由基.在多晶Au衬底上，在470 K时观察到金属镓，而Cls信号消失。在266 nm处，单层Ga（CH_3）_2的光解离产生了Si片上CH_n自由基和Ga金属的XPS谱，而在355 nm处没有观察到分解，在100 K下，用193或351 nm的激光照射Si片上的Cl_2或CH_3Cl多层膜，导致这些分子的光解离和光刻产物的形成。测量了光碎片（Cl、CH_3）和刻蚀产物（SiCl、SiClC_2）的动能分布。Cl或CH_3在基体上沉积较薄时的动能分布为双峰分布，用共振增强多光子电离技术，观察了HCl和HBr在真空紫外区光解产生的氢原子光碎片的多普勒轮廓，确定了高电子态的对称性（R = CH_3，C_2H_5，C_3H_7，C_4H_9）、氯代甲烷（CH_nCl_<4-n>）和氟代氯代甲烷（CF_nCl_<4-n>）在真空紫外区发生光解离。用共振增强多光子电离技术探测氯原子的光碎片。电子态的对称性由光碎片的角分布确定。

Pyrolytic and photolytic dissociation of trimethylgallium on Si, Au, and Al substrates was studied by X-ray and UV photoelectron spectroscopy technique. On an Si (111) substrate, gallium metal and CH_n radicals are deposited by pyrolytic dissociation up to 670 K. On a polycrystalline Au substrate, gallium metal was observed while Cls signal disappeared at 470 K. Photodissociation of monolayered Ga(CH_3)_2 at 266 nm gives XPS spectra for CH_n radicals and Ga metal on the Si wafer while at 355 nm no decomposition was observing.Laser irradiation at 193 or 351 nm of a multilayer of Cl_2 or CH_3Cl on an Si wafer at 100 K leads to both photodissociation of these molecules and formation of photoetching products. The kinetic energy distributions of photofragments (Cl, CH_3) and etching products (SiCl, SiCiC_2) were measured. The kinetic energy distribution of Cl or CH_3 is bimodal for the case of thin deposition of parent molecules on substrates.The Doppler profiles of the hydrogen atom photo fragments from the photodissociation of HCl and HBr at vacuum UV region are observed to determine the symmetries of the higher electronic states by using a resonance enhanced multiphoton ionization technique.Alkyl chlorides (R = CH_3, C_2H_5, C_3H_7, and C_4H_9), chloromethanes (CH_nCl_<4-n>), and chlorofluoromethanes (CF_nCl_<4-n>) are photodissociated at vacuum UV region. The chlorine atom photo fragments are detected by a resonance-enhanced multiphoton ionization technique. The symmetries of the electronic states are determined from angular distributions of photofragments.