Effect of preamorphization implantation on C54-TiSi2 formation in salicided narrow lines

The effect of the preamorphization implantation (PAI) process on TiSi2 phas e transformation has been investigated by using arrays of submicron TiSi2 l ines. The C49-C54 transformation of TiSi2 during annealing is promoted by t he PAI process. The promotion of phase transformation cannot be explained o nly by the difference in grain size of the C49-TiSi2; hence, the nucleation site density for the phase transformation was estimated. The epitaxial rel ation with the Si substrate also retards the C49-C54 phase transformation. The epitaxial growth of C49-TiSi2 on the Si substrate is observed in a larg e portion of C49-TiSi2 grains in the sample without PAI, whereas orientatio n of C49-TiSi2 in the sample with PAI has no relation to that of the Si sub strate. Epitaxial C49-TiSi2 is more stable and is difficult to phase transf orm. After phase transformation, the C54-TiSi2 oriented to the < 004 > dire ction is predominant in the samples without PAI. The strong orientation of C54 < 004 > resulted from one-dimensional growth along submicron lines enha nced by the low density of the nucleation site. On the other hand, in the s ample with PAI, an increase in the nucleation site leads to two-dimensional growth, and C54-TiSi2 films exhibit a random orientation with a weak domin ant C54 < 311 > orientation. (C) 1999 American Institute of Physics. [S0021 -8979(99)03106-0].