| 摘要 |
PURPOSE:To form a PSG of high quality for short time by heating a semiconductor substrate while irradiating far ultraviolet rays thereto with PH3, SiH4 and N2O as reaction gases. CONSTITUTION:An Si substrate completely formed with elements and wires thereon is contained in a furnace, mixture gas of SiH4 including 2-10% of PH3 and N2 gas of 5-10 times the SiH4 is introduced with H2 as carrier gas, and the interior of the furnace is retained at 1-10Torr. Far ultraviolet rays are irradiated through the upper eall of the furnace, and N2O is thus excited, and the substrate is ratied at approx. 350 deg.C while activating the growing gas. SiO2.P2O5 is formed with the activated O*. According to such a method the growing temperature may be lowered by approx. 100 deg.C as compared with the ordinary pressure-reduced CVD process, and the growing speed becomes approx. 10 times. Thus, the PSG film can be obtained for short time. This reaction for producing the film is conducted on the surface of the substrate. The film thus becomes dense without causing vapor phase decomposition, and the PSG film having excellent insulating and protecting effects can be obtained. |
