Low-temperature polycrystalline silicon deposition by very high frequency sputtering using Ar and H-2

Polycrystalline silicon thin films have been deposited on silicon oxide at 300 degrees C by very high frequency (182.5 MHz) sputtering using an Ar and H-2 gas mixture and an arsenic-doped Si wafer target. Characteristics of films are affected by the hydrogen partial pressure, and polysilicon of lowest resistivity is obtained at 20 to 30% hydrogen partial pressure ratio-We found that as the hydrogen content of the film is reduced, resistivity decreases. This is attributed to reduction of amorphous grain boundary regions due to better crystallization. It is also found that the normalized ion flux incident on the growing surface varies with hydrogen partial pressure, an important parameter for determining the properties of as-deposited polysilicon.