A microwave discharge utilizing a spokewise antenna was successfully applied for high rate deposition of microcrystalline silicon (muc-Si:H) film at low substrate temperatures of 200-250 degreesC. Systematic deposition studies were carried out with the total pressure, H-2 dilution ratio and flow rate of SiH4, Fr(SiH4), as variables, combined with optical emission spectroscopy (OES) and Langmuir probe characterizations. It was revealed that the total pressure was the most important parameter for determining the deposition rate, which exhibited a maximum at 40-50 mtorr along with good crystallinity. By optimizing the plasma parameters together with the axial distribution of electron density, n(e), a high deposition rate of similar to 47 Angstrom /s is achieved in the highly crystallinitzed and photoconductive muc-Si:H growth. A correlation among OES signal intensity, SiH, the intensity ratio, I-H alpha/I-Si*, deposition rate and film crystallinity is demonstrated.