A. Weber et al., LOW-TEMPERATURE DEPOSITION OF TIN USING TETRAKIS(DIMETHYLAMIDO)-TITANIUM IN AN ELECTRON-CYCLOTRON-RESONANCE PLASMA PROCESS, Journal of the Electrochemical Society, 141(3), 1994, pp. 849-853
High quality TiN layers were deposited in an electron cyclotron resona
nce (ECR) plasma process at substrate temperatures between 100 and 60-
degrees-C. Tetrakis(dimethylamido)-titanium [Ti(NMe2)4] was used as th
e precursor and introduced into the downstream region of an ECR plasma
. Nitrogen or ammonia have been used as plasma gases. The electrical p
roperties and the film compositions of the gold-colored TiN layers mai
nly depend on the deposition rate. ECR plasma-activated nitrogen or am
monia reacts with Ti(NMe2)4 to form low resistivity (100-150 muOMEGAcm
) crystalline TiN films even at a substrate temperature of 100-degrees
-C. Films deposited between 200 and 600-degrees-C exhibited resistivit
ies that decreased from 100 to 45 muOMEGAcm. Crystalline orientation i
s influenced by the chosen plasma gas. Preferred growth in the (111) a
nd (100) directions were found by using ammonia and nitrogen, respecti
vely The measured resistivities and deposition temperatures are the lo
west reported values for a plasma-enhanced TiN deposition process. Exp
eriments with labeled nitrogen show that the nitrogen for the TiN form
ation is almost exclusively derived from the plasma gas. The deposits
were characterized by four-point probe resisivity measurements, x-ray
diffraction, forward recoil scattering, and Rutherford backscattering
spectrometry. Step-coverage was checked by a scanning electron microsc
opy cross section of a contact via.