| 摘要 |
PURPOSE:To realize high integration density of LSI by forming a first and a second films on the one main surface of a semiconductor substrate, removing the second film at the level-different section, forming a sharp groove to the one main surface of substrate, and thereafter burying the groove with an insulator which becomes the inter-element isolation layer. CONSTITUTION:After a thin thermal oxide film is formed on the surface N<-> type silicon semiconductor substrate 11, a silicon nitride film 12 is deposited. The surface is then coated with a PSG film 13 and moreover a photo resist film 14. Next, it is then patterned. A plasma nitride film 16 is deposited on the entire surface of semiconductor substrate 11 and this film 16 is then etched. The PSG film 13 is removed by the lift-off processing. When the semiconductor substrate 11 is dry-etched, a sharp groove 18 is formed on the surface of semiconductor substrate. After, the ion of N type impurity 19 such as phosphorus, etc. is implanted and the semiconductor substrate 11 is heat-processed at a high temperature. An insulator insulator 23 consisting of SiO2 is left only at the groove 18 by etching back of the SiO2 film 23 with dry-etching method and the inter- element isolation layer 10 obtained by burying the groove 18 with insulator completed. |
