【摘要】 采用角分辨分子束散射技术研究了Cl₂与InP（100）表面热反应和激光诱导反应产物的角分布.对于热反应,由调制分子束和可转动四极质谱仪测得产物离子InCl⁺、InCl₂⁺、PCl⁺、PCl₂⁺和P₄⁺的角分布,都可用cos^1·（?）θ函数报合.对于紫外（355nm）激光诱导反应,由飞行时间质谱法测得主要产物离子的角分布明显地偏离Knudsen 定律.其中In⁺,InCl⁺和InCl₂⁺的角分布可用α·cosθ+（1-α）cosⁿθ函数拟合,其中α和n为拟合参数,对于不同的产物离子有不同的数值.由实验测得的脱附粒子的通量和能量在表面法线方向有明显地聚集现象,可以认为产物从表面上脱附的机理,除了热脱附之外,还有非热脱附以及在表面附近脱附粒子的碰撞效应.更多还原

【Abstract】 Angle-resolved supersonic molecular beam scattering techniques are used to exa-mine the angular distributions of the products formed in thermal and UV laser-inducedreactions of chlorine molecular beam with InP（100） surface.For the thermal reaction,the angular distributions of InCl₂⁺,InCl⁺,PCl⁺,PCl₂⁺ and P₄⁺ products are slightlypeaked towards the normal of the surface and vary as cos（?）θ,θ being the detection angle from the surface normal.The effect of the normal components of the transla-tional energies of Cl₂ molecules is also observed at different angle of incidence.Under355 nm pulsed laser irradiation,the time-of-flight（TOF）spectra of InCl⁺ are mea-sured as a function of the detection angle and Maxwellian characterized with themean kinetic energy or translational temperature.The flux distributions are sharperthan cosine law and can be fitted by an expression of F（θ）=a·cosθ+（1-a）cosⁿθ,where a and n are adjustable parameters.The mean kinetic energy distribution ofInCl molecules is strongly peaked around the surface normal and decreases with in-creasing the detection angle.These results imply that both thermal and nonthermaldesorption mechanisms are important in the UV laser-induced reaction processes.更多还原