Method for uniform nanoscale film deposition
View Patent ↗Ultrathin layers are deposited by chemical vapor deposition (CVD) with reduced discontinuities, such as pinholes. Embodiments include depositing a material on a wafer by CVD while rotating the CVD showerhead and/or the wafer mounting surface, e.g., at least 45°. Embodiments include rotating the showerhead and/or mounting surface continuously through the deposition of the material. Embodiments also include forming subfilms of the material and rotating the showerhead and/or mounting surface after the deposition of each subfilm. The rotation of the showerhead and/or mounting surface averages out the non-uniformities introduced by the CVD showerhead, thereby eliminating discontinuities and improving within wafer and wafer-to-wafer uniformity.
1. A method of manufacturing a semiconductor device, the method comprising depositing a plurality of sub-films of a material on a wafer, by chemical vapor deposition (CVD), using the same CVD showerhead for all of the sub-films, and rotating the wafer relative to the CVD showerhead about a vertical axis through the center of the wafer and/or rotating the CVD showerhead relative to the wafer about a vertical axis through the center of the CVD showerhead to a different relative position of the wafer and CVD showerhead, during a break in deposition after the deposition of each sub-film.
2. The method according to claim 1 , comprising depositing the material at a total thickness of about 50 Å or less.
3. The method according to claim 1 , comprising rotating the CVD showerhead.
4. The method according to claim 1 , comprising rotating the wafer and/or CVD showerhead at least three times.
5. The method according to claim 4 , comprising rotating the wafer and/or CVD showerhead a total of at least about 45°.
6. The method according to claim 5 , comprising rotating the wafer and/or CVD showerhead a total of about 45° to about 90°.
7. The method according to claim 6 , comprising rotating the CVD showerhead.
8. The method according to claim 1 , further comprising forming a layer containing copper on the wafer, and depositing the material on the layer.
9. The method according to claim 8 , comprising depositing a silicon nitride capping material on the layer.
10. The method according to claim 1 , comprising depositing the material by metal organic chemical vapor deposition (MOCVD).
11. A method of manufacturing a semiconductor device, the method comprising: forming a layer containing copper on a wafer;
depositing by CVD a silicon nitride capping material as a series of sub-films, using the same CVD showerhead for all of the sub-films, to a total thickness of about 50 Å or less on the layer containing copper; and
rotating the wafer relative to the CVD showerhead about a vertical axis through the center of the wafer and/or rotating the CVD showerhead relative to the wafer about a vertical axis through the center of the CVD showerhead, during a break between the depositions of each adjacent pair of sub-films, for a total rotation of about 45° to about 90° about the vertical axis.