| 摘要 |
PURPOSE:To prevent extension of diffusion length and lowering of reliability on deterioration of element characteristics by using 'on-the-place adding method' in which impurity gas is added into active gas so as to accumulate a doping layer directly. CONSTITUTION:After forming an insulating film 7 consisting of a silicon oxide film on a lower electrode 7, a polycrystalline silicon layer 18 doped with phosphorous in high concentration is accumulated by 'on-the-place adding method'. Hereupon, a substrate 1 is installed in a CVD device, and after letting only silane gas flow, phosphine gas is added so as to accumulate a polycrystalline silicon layer 18 which is doped with phosphorus in high concentration with a thickness of 2000Angstrom at the substrate temperature of 600 deg.C, and this is patterned so as to form the pattern of an upper electrode 18. Hereafter, heat treatment at 1050 deg.C is done for 15 seconds. Accordingly, a MOS capacitor which caught the insulating film 7 with the upper electrode 18 and the lower electrode 6 is formed, and a memory cell consisting of a MOS FET and a MOS capacitor can be obtained. Hereby, it becomes one that the extension of a diffusion layer is also small, the characteristics are excellent even for high integration, and reliability is high. |
