| 摘要 |
PURPOSE: A method for manufacturing a transistor is provided to prevent a refresh characteristic from being degraded by forming an oxynitride layer only on a part of a gate oxide layer and using the transistor as a dynamic random access memory(DRAM) device, and to improve reliability by forming the oxynitride layer on an interface between the gate oxide layer and a borosilicate glass(BSG) layer to prevent penetration of boron ions. CONSTITUTION: A gate oxide layer(22) and a polysilicon layer(23) are sequentially deposited on a semiconductor substrate(21), and patterned to a region where a gate is to be formed. Nitrogen ions are tilt-implanted into the resultant structure to form an oxynitride layer(24) in a side surface of a portion where the gate oxide layer is exposed. A borosilicate glass(BSG) layer(25) and a nitride layer are sequentially formed on the resultant structure, and the nitride layer is etched to form a nitride layer sidewall. The BSG layer is etched by using the nitride layer sidewall as a mask. High-density impurity ions are implanted into the semiconductor substrate to form a p-type high-density source/drain region(27) by using the resultant structure as a mask. A heat treatment is performed regarding the resultant structure to enlarge the high-density source/drain region. Boron ions inside the BSG layer are penetrated into the semiconductor substrate to form a low-density source/drain region(28).
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