Material and Electrical Characterization of Nickel Silicide-Carbon as Contact Metal to Silicon-Carbon Source and Drain S
- PDF / 1,648,396 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 42 Downloads / 169 Views
0995-G05-07
Material and Electrical Characterization of Nickel Silicide-Carbon as Contact Metal to Silicon-Carbon Source and Drain Stressors Rinus Tek Po Lee1, Li-Tao Yang1, Kah-Wee Ang1, Tsung-Yang Liow1, Kian-Ming Tan1, Andrew See-Weng Wong2, Ganesh S. Samudra1, Dong-Zhi Chi2, and Yee-Chia Yeo1 1 Electrical and Computer Engineering, National University of Singapore, Block E4A #02-04 Engineering Drive 3, Singapore, 117576, Singapore 2 Institute of Materials Research and Engineering, 3 Research Link, Singapore, 117602, Singapore ABSTRACT In this paper, the material and electrical characteristics of Nickel-Silicon-Carbon (NiSi:C) films were investigated for the first time to ascertain the compatibility of NiSi:C contacts to silicon-carbon (Si:C) source/drain stressors. The incorporation of 1 atomic percent of carbon was found to increase both the Ni2Si-to-NiSi and NiSi-to-NiSi2 transformation temperatures. Our results show that the incorporation of carbon stabilizes the interfacial and surface morphology of NiSi:C films. We speculate that the incorporated carbon segregates into the NiSi:C grain boundaries and suppresses film agglomeration and NiSi-to-NiSi2 phase transformation. X-ray diffraction analysis further revealed that the formed NiSi:C films possessed a preferred orientation. Current-voltage measurements for NiSi and NiSi:C n+/p junctions exhibit similar cumulative distribution for junction leakage indicating that carbon incorporation does not have a detrimental impact on the n+/p junction integrity. Our results suggest that NiSi:C is a suitable self-aligned contact metal silicide to n-channel MOSFETs with SiC S/D stressors in a similar manner to the way in which NiSiGe is used for p-channel MOSFETs with SiGe S/D stressors. INTRODUCTION Lattice-mismatched source and drain (S/D) stressors are being actively pursued to enhance carrier mobility and drive current performance of nanoscale metal-oxide-semiconductor field-effect transistors (MOSFETs) [1]-[3]. For p-channel MOSFETs, the use of silicongermanium (SiGe) S/D stressor introduces uniaxial compressive strain in the channel and improves the drive current significantly [3]. Conversely, silicon-carbon (Si:C or SiC) S/D stressor introduces uniaxial tensile strain in the channel beneficial for n-channel MOSFET drive current enhancement [1],[2],[4]-[6]. In order to reap the full benefits of channel strain engineering, it will be imperative to integrate the new materials (i.e. SiGe and SiC) with low resistance silicide technology [7]. Nickel-germanosilicide (NiSiGe) is compatible with SiGe technology and adopted as the contact metal for strained p-channel MOSFETs in high-volume manufacturing. However, literature on the material and electrical characteristics of nickel silicide-carbon (NiSi:C) as contact metal to SiC is currently lacking. In this paper, we report experimental results on the NiSi:C phase formation, interfacial/surface morphologies, and junction integrity to ascertain the compatibility of NiSi:C contacts to Si:C S/D stressors.
EXPERIMENTAL SETUP 2
Data Loading...
