| 摘要 |
PURPOSE:To obtain a polycrystalline silicon thin film having an excellent step coverage and a low resistance by depositing an amorphous silicon while mixing with impurity and polycrystallizing it by later heat treating. CONSTITUTION:An oxide film 2 having a groove is formed on a silicon substrate 1, and an amorphous silicon 3 is deposited thereon by using a vertical CVD unit, holding at 450-550 deg.C of a depositing temperature, feeding disilane as growing gas, PH3 dilute gas with He as impurity and N2 gas. Thereafter, obtained amorphous silicon is heat treated at 900 deg.C in a nitrogen atmosphere, and completely crystallized. As a result, a polycrystalline silicon thin film having an excellent step coverage and a low resistance can be obtained, and capacity characteristics of a semiconductor memory are improved. |
