Investigation of the Effects of Very Low Pressure Chemical Vapor Deposited TiSi2 on Device Electrical Characteristics

Abstract

We report for the first time the effects of very low pressure chemical vapor deposited (VLPCVD) titanium silicide on device electrical characteristics. The compatibility of this material for VLSI technology is examined through careful characterization of the shallow junction and gate oxide integrities, sheet resistance, and contact resistivity. It is shown that the integrity of the shallow junctions is preserved if the silicon consumption during the silicide deposition is controlled. If this consumption is not controlled, a Schottky diode behavior is observed for the source/drain junctions. It is shown that titanium silicide lowers the specific contact resistivity of metal/source-drain and metal/polysilicon structures by an order of magnitude and a factor of 4-5, respectively. The sheet resistance of the doped polysilicon (gate conductor) is reduced by more than two orders of magnitude through using a TiSi2/polysilicon structure. In addition, it is shown that VLPCVD titanium silicide has no significant effect on the quality of the gate oxide. Slightly lower breakdown voltages for the TiSi2/ polysilicon capacitors are measured, which could be due to the stress induced by siliciding the gate. The results presented in this paper indicate the suitability of VLPCVD titanium silicide films for high quality device fabrication.ABSTRACT A mechanistic study of oxide deposition from silane and nitrous oxide between 495~ and 690~ was performed in a laminar flow, cool wall reactor. Results indicated the existence of two distinct chemical pathways. At high nitrous oxide concentrations, the deposition reaction is dominated by radical chain chemistry initiated by the decomposition of N20. At lovcer N20 concentrations, the decomposition of siIane to form silylene (SiH~) initiates the deposition. Studies of the reaction of disilane and nitrous oxide confirmed the role of Sill2 in the deposition. Reactions involving Sill2 are used to explain the observed growth of sub-stoiehiometric oxides under low N20 conditions. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 128.122.253.212 Downloaded on 2015-06-06 to IP

High Doping Density/High Electric Field, Stress and Heterojunction Effects on the Characteristics of CMOS Compatible p-n Junctions

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Characteristics of the nanoscale titanium film deposited by plasma enhanced chemical vapor deposition and comparison of the film properties with the film by physical vapor deposition

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