  We study temperature evolution of spin accumulation signals obtained by the
three-terminal Hanle effect measurements in a nondegenerated silicon channel
with a Schottky-tunnel-barrier contact. We find the clear difference in the
temperature-dependent spin signals between spin-extraction and spin-injection
conditions. In a spin-injection condition with a low bias current, the
magnitude of spin signals can be enhanced despite the rise of temperature. For
the interpretation of the temperature-dependent spin signals, it is important
to consider the sensitivity of the spin detection at the
Schottky-tunnel-barrier contact in addition to the spin diffusion in Si.
