| 摘要 |
PURPOSE:To lower hold time defect of MOS memory IC by executing thermal processing in the ambient including oxygen and eliminating surface layer after BSD manufacturing to the mirror-surfaced wafer. CONSTITUTION:The BSD process has been executed by spraying grain in average size of 10mum with a pneumatic pressure of 1.5kg/cm to the P type 7- 10OMEGA-cm, 100phi, 525mum wafer obtained through slice process, chamfering process, wrapping process and etching process from the CZ dislocation-free single crystal containing oxygen concentration of 14-18X10<17>atoms/CC. After washing said mirror-surfaced wafer, it is subjected to the thermal processing for an hour or longer at a temperature of 1,100-1,200 deg.C under the ambient where oxygen of 3-10%, for example, 5% is added to Ar gas, for example, it is subjected to the thermal processing for six hours at 1,150 deg.C, an oxide film of said mirror-surfaced wafer is removed by the rare fluoric acid, and the surface rayer in the opposite side of BSD processed surface is removed in the range of 0.5-20mum, for example, 10-20mum by the mirror surface polishing. |
