Low-temperature surface cleaning method using low-energy reactive ionized species

A new low-temperature Si substrate surface cleaning method using low-energy controlled ionized species produced from H2 or H2-SiH4 electron-cyclotron-resonance plasma is described. This method is based on the reactive ion beam deposition technique, which opened up the possibility for lowering the crystalline Si film growth temperature. By irradiating the 50–300-eV ionized species produced from H2-SiH4 plasma onto the single-crystal Si(111) and Si(100) substrates, thoroughly clean surfaces were obtained at the low temperature of 650 °C. These cleaned substrate surfaces exhibited superstructures, such as Si(111)-7×7 and Si(100)-two-domain-2×1.