  Magnetic skyrmions have been suggested as information carriers for future
spintronic devices. As the first material with experimentally confirmed
skyrmions, B20-type MnSi was the research focus for decades. Although B20-MnSi
films have been successfully grown on Si(111) substrates, there is no report
about B20-MnSi films on Si(100) substrates, which would be more preferred for
practical applications. In this letter, we present the first preparation of
B20-MnSi on Si(100) substrates. It is realized by sub-second solid-state
reaction between Mn and Si via flash-lamp annealing at ambient pressure. The
regrown layer shows an enhanced Curie temperature of 43 K compared with bulk
B20-MnSi. The magnetic skyrmion signature is proved in our films by magnetic
and transport measurements. The millisecond-range flash annealing provides a
promising avenue for the fabrication of Si-based skyrmionic devices.
