| 摘要 |
A method for manufacturing a shallow trench isolation structure. A two-stage process is performed to form a trench. An anisotropic etching operation is conducted to form a smaller trench, and then an isotropic etching operation is conducted to form a wider trench underneath. Hence, a portion of trench extends into the substrate below the device-forming regions. An insulating material is deposited to fill the trench. Therefore, the degree of electrical insulation between devices in neighboring active regions is increased without affecting the layout of device on the substrate. Moreover, the degree of overlap between the source/drain region and the substrate is reduced. Hence, junction capacitance is lowered and operating speed of the device is increased.
|
