KINETIC-ENERGY DEPENDENCE OF DISSOCIATIVE CHARGE-TRANSFER REACTIONS OF HE+, NE+, AR+, KR+, AND XE+ WITH SILANE

Guided ion-beam techniques are used to measure the cross sections as a function of kinetic energy for reaction of SiH4 with He +, Ne +, Ar +, Kr +, and Xe +. State-specific data for the 2P3/2 ground spin-orbit states of Kr+ and Xe+ are also obtained. The products observed in the He, Ar, and Kr systems are SiHx+ for x=0-3. For the Ne system, formation of SiHx+ x = 0-2, is seen, while in the Xe system only SiH3+ and SiH2+ are observed. Reactions of He + , Ne + , Kr + , and Xe + show little dependence on kinetic energy, but for the case of Ar + , the reaction probability and the product distribution are highly sensitive to the kinetic energy of the system. Thermal reaction rates for all of the reactions are derived and compared with previous measurements. The results for these reactions are explained in terms of vertical ionization from the 1t2 and 3a1 bands of SiH4. The relationships of these reactions to plasma deposition and etching are also discussed. © 1990 American Institute of Physics.