TENSILE STRESSED DOPED AMORPHOUS SILICON

摘要

The method and apparatus disclosed herein relate to preparing a stack structure for an electronic device on a semiconductor substrate. A particularly beneficial application of the method is in reduction of internal stress in a stack containing multiple layers of silicon. Typically, though not necessarily, the internal stress is a compressive stress, which often manifests as wafer bow. In some embodiments, the method reduces the internal stress of a work piece by depositing phosphorus doped silicon layers having low internal compressive stress or even tensile stress. The method and apparatus disclosed herein can be used to reduce compressive bow in stacks containing silicon.

主权项

1. A method of preparing a stack structure for an electronic device on a semiconductor substrate, the method comprising:
(a) depositing a doped silicon layer on the substrate by introducing a first process gas comprising a silicon hydride and a dopant precursor into a chemical vapor deposition (CVD) apparatus having a plasma, wherein the substrate is held at a temperature of about 450° C. to 550° C., the silicon hydride in the first process gas is introduced at a flow rate of at least about 0.01 sccm/cm2 of substrate deposition surface area, and the doped silicon layer has a compressive stress of less than about 100 MPa or a tensile stress, and a thickness of less than about 500 Å; (b) depositing a dielectric layer on the substrate by introducing a second process gas comprising a precursor of the dielectric layer into the CVD apparatus having a plasma, wherein the dielectric layer has a compressive stress of at least about 200 MPa and a thickness of less than about 500 Å; and (c) repeating operations (a) and (b) for two or more times to form a stack structure.