| 摘要 |
A method for forming an isolation layer in a semiconductor device includes forming a trench in a semiconductor substrate. A liner layer that includes a liner nitride layer and a liner oxide layer is formed on an exposed surface of the trench. A flowable insulation layer is formed to fill the trench. The flowable insulation layer is recessed to expose a portion of the liner nitride layer on an upper portion of the trench. A first preheating process is performed to release stress of the liner layer. A second preheating process is performed to oxidize the exposed liner nitride layer. A buffer layer is formed on a portion of the liner layer that is formed on a sidewall of the trench and exposed after the flowable insulation layer is recessed. The buffer layer is etched to smoothen a rough portion of the liner layer that is formed when the flowable insulation layer is recessed. A buried insulation layer is deposited in the trench. |
