Single-crystal InAs films are grown by metalorganic chemical Vapor deposition on vicinal GaAs(100) substrates in the temperature range of 350-550 degreesC. We employed for the first time in InAs growth in situ plasma-generated arsine radicals as the group V source, trimethylindium as the group III source, and hydrogen as the carrier gas. The in situ generated arsine is produced by placing solid arsenic downstream of a microwave hydrogen plasma. The Arrhenius plot of InAs growth rate vs. reciprocal growth temperature shows an activation energy of 10 kcal/mol in the 350-450 degreesC temperature range, and a rapidly decreasing growth rate at temperatures above 450 degreesC, neither of which has been reported to our knowledge in the literature.