Suppression of oxidation enhanced boron diffusion in silicon by carbon implantation and characterization of MOSFETs with carbon implanted channels

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:621324

Ban, I; Oeztuerk, M C ^[1]; Demirlioglu, E ^[2]

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1. North Carolina State Univ., Raleigh, NC (United States)
2. National Semiconductor Corporation, Santa Clara, CA (United States)

Scaling of MOSFETs into the deep submicron regime requires shallow doping profiles with abrupt doping transitions in the MOSFET active region. In NMOS transistors with boron doped channels, oxidation enhanced diffusion is a key contributor to boron profile broadening. Starting from the arguments presented in several recent reports on the role of carbon in silicon as a sink for self-interstitials, we have explored the feasibility of using carbon in the MOSFET in the active region to retard boron diffusion during gate oxidation. MOSFETs with carbon and boron implanted channels have been fabricated. Boron diffusion, activation, and critical electrical parameters such as subthreshold swing, threshold voltage, and off-state leakage current have been evaluated as a function of the carbon dose. We have shown that carbon can effectively suppress boron diffusion during gate oxidation. However, at dose levels around 10{sup 14}cm{sup -2} carbon results in poor boron activation and degradation in MOSFET performance.

• OSTI ID: 621324
• Report Number(s): CONF-9606110--; CNN: Grant 8721545; Grant 95-SJ-081
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BORON IONS
CARBON IONS
DIFFUSION
INTERSTITIALS
ION IMPLANTATION
LEAKAGE CURRENT
MOSFET
OXIDATION
SILICON