Raman and Fourier Transform Infrared Spectroscopy Characterization of Nickel Silicides

Abstract

<p>The purpose of this study was to identify nickel sihcide phases which were produced by rapid thermal annealing (RTA) at different temperatures, to examine the dependence of nickel sihcide growth on dopant species of the substrate, and to compare growth kinetics to previously observed growth patterns reported in literature. Six mckelsihcide thin film samples were prepared on eight-mch crystalline silicon wafers (100 surface) for the study Prior to the preparation of the sihcide films, all wafers received a dopant and dopant activation step Three wafers received a boron dopant, and three wafers received a phosphorous dopant; dopant concentrations were 10(15) cm (-3) Then a 19 nm thick layer of nickel metal was deposited onto all wafers. Finally, each wafer received one of three different RTA treatments to create the silicide layer. These treatments were all done for thirty seconds and differed only m the temperature chosen. These temperatures were: 380C, 450C, and 850C</p>

<p>The Raman analysis was done at Advanced Micro Devices in the Process Characterization and Analysis Laboratory The FTER analysis was done at Texas State University in the laboratory of Dr. David Donnelly.</p>

<p>Peaks observed in the Raman spectra of the samples corresponded to previously reported peaks for NiSi. This enabled the identification of this silicide phase. However, growth kinetics differed from the thin film kinetics observed in other reports, which were expected to occur in this study. The silicides were expected to appear sequentially in the order: Ni2Si, N1S1, NiSi2. In contrast, the Raman spectra gathered from the samples suggested the growth of the NiSi layer occurred before all the nickel metal was consumed. In addition, the growth rate of nickel monosilicide showed a dependence on dopant species.</p>