| 摘要 |
PURPOSE: A method of forming a trench isolation is to prevent the diffusion of boron and phosphorus ions included in a BPSG layer to the exterior, thereby stabilizing the electric properties of a semiconductor device. CONSTITUTION: An active region in a silicon substrate(1) is selectively etched to form a trench therein. BPSG layer(4) is buried into the trench. Thereafter, a cleaning process is performed on the entire structure utilizing DI water with ozone dissolved therein, to form a thin native oxide layer(5) on the BPSG layer. The native oxide layer is relatively dense in film quality, so that it prevents the diffusion of boron and phosphorus ions into an upper layer in a subsequent annealing process.
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