Synthesis of TiN, Ti, and TiSi.sub.2 Thin Films for the Contact System of Solar Cells

The influence of deposition parameters, such as: the magnetron power in the range 690-1400 W, the silicon substrate temperature 23-170°C, the N.sub.2 gas flow rate 0.9-3.6 L/h, the Ar gas flow rate 0.06â3.6 L/h, the ratio of N.sub.2/Ar gas flows 1-60 on the thickness, the density, and the composition of the deposited films is analyzed. The maximum density 5.247 g/cm.sup.3 corresponding to the TiN.sub.0.786 = Ti.sub.56N.sub.44 composition has been achieved at the following deposition parameters: 1200 W, N/Ar = 1.8/0.06 L/h = 30, 0.8 Pa, 320 s, and 100°C. At temperatures 700-800°C, the mutual diffusion of titanium and silicon atoms through the interface leads to the active nucleation, the formation of nanocrystals and low-resistance metallization layers. X-ray diffraction shows that, during annealing at 700°C (30 min, Ar), the formation of phase TiSi.sub.2 due to the diffusion of Ti atoms into silicon is twice more intense than the formation of Ti.sub.5Si.sub.3 due to the diffusion of silicon atoms into titanium as a result of high hardness of titanium. The average sizes of TiSi.sub.2 decreases from 7.1 to 5.6 nm at 750°C due to the crystallization of the nuclei and increase to 9.2 nm at 800°C.