Activation of the Formation of Titanium Nitride Thin Film by Chemical Vapor Deposition

首先，分析了氢气还原硼氢化物化学气相沉积硼的实验速率数据。钨被用作衬底。在表面反应控制下，硼和氢的反应级数分别为三分之一和二分之一。通过比较这些顺序与从langmuir-hinshelwood型方程得到的顺序，速率控制机制已被建议为氯化氢从基板的解吸。其次，分析了以H_2、N_2和TiCl_4为反应气体的化学气相沉积氮化钛的实验速率数据。在表面反应控制下，沉积速率分别与氢分压和氮分压的平方根成正比。沉积速率随TiCl_4分压的增加而降低。通过与langmuir-hinshelwood型方程的比较，提出了反应的速率控制步骤可能是氢原子与氮原子在反应表面上的反应或氢分子与氮分子在表面上的吸附。当TiCl_4分压增加时，由于竞争吸附，这些原子的表面覆盖程度降低。最后，在表面反应控制机制下，研究了光辐照对TiN沉积速率的影响。光的波长为253.7 nm。在气体上照射的沉积速率小于没有照射的沉积速率。认为TiCl_4蒸气在光照射下活化，TiCl_4的表面覆盖度增加，而速率控制步骤中的反应物H_2和N_2的表面覆盖度减少。当衬底被辐照时，观察到TiN形成的活化。

Firstly, experimental rate data on the chemical vapor deposition of boron by reduction of boron trichloride with hydrogen are analyzed. Tungsten was used as the substrate. Under surface reaction control regime, the reaction orders with respect to boron trichloride and hydrogen are one-third and one-half, respectively. By comparing these orders with those obtained from langmuir-hinshelwood type equations, the rate controlling mechanism has been suggested to be the desorption of hydrogen chloride from the substrate. Secondly, experimental rate data of chemical vapor deposition of titanium nitride from the reactant gases H_2, N_2 ant TiCl_4 were analyzed. Under surface reaction control regime, the deposition rate was in proportion to the square root of the partial pressures of hydrogen and nitrogen, respectively. The deposition rate decreased with increasing partial pressure of TiCl_4. By comparing these results with langmuir-hinshelwood type equations, it has been suggested that the probable rate-controlling step is the reaction of hydrogen atoms with nitrogen atoms on the reaction surface or the adsorption of hydrogen molecules and that of nitrogen molecules on the surface. The extent of surface coverage by these atoms is considered to have been reduced when the partial pressure of TiCl_4 is increased, due to competitive adsorption. Finally, the effects of light irradiation on the deposition rate of TiN were investigated under surface reaction control regime. The wave length of the light is 253.7 nm. The deposition rate with irradiation on the gases was smaller than that without irradiation. It is considered that TiCl_4 vapor becomes active with light irradiation and the extent of surface coverage by TiCl_4 is increased, and that by hydrogen and nitrogen which are reactants in the rate-controlling step has been reduced. When the substrate was irradiated, the activation of the formation of TiN was observed.