Low-k Dielectric and Processes for Forming Same
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChia Cheng CHOU, Li Chun TE, Po-Cheng SHIH, Tien-I BAO
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Abstract
Embodiments described herein relate generally to methods for forming low-k dielectrics and the structures formed thereby. In some embodiments, a dielectric is formed over a semiconductor substrate. The dielectric has a k-value equal to or less than 3.9. Forming the dielectric includes using a plasma enhanced chemical vapor deposition (PECVD). The PECVD includes flowing a diethoxymethylsilane (mDEOS, C5H14O2Si) precursor gas, flowing an oxygen (O2) precursor gas; and flowing a carrier gas. A ratio of a flow rate of the mDEOS precursor gas to a flow rate of the carrier gas is less than or equal to 0.2.
Claims21
A method comprising:
- forming a dielectric over a semiconductor substrate, the dielectric having a k-value equal to or less than 3.9, forming the dielectric comprising using a plasma enhanced chemical vapor deposition (PECVD), wherein the PECVD includes:
- flowing a diethoxymethylsilane (mDEOS, C5H14O2Si) precursor gas;
- flowing an oxygen (O2) precursor gas;
- and
- flowing a carrier gas, wherein a ratio of a flow rate of the mDEOS precursor gas to a flow rate of the carrier gas is less than or equal to 0.2.
A method comprising:
- forming a dielectric layer over a semiconductor substrate, forming the dielectric layer comprising using a first plasma enhanced chemical vapor deposition (PECVD) that uses a first diethoxymethylsilane (mDEOS, C5H14O2Si) precursor gas and a first carrier gas, wherein during the first PECVD:
- a flow rate of the first mDEOS precursor gas is equal to or less than 6 sccm;
- and
- a flow rate of the first carrier gas is equal to or greater than 3,000 sccm;
- forming an opening through the dielectric layer;
- and
- forming a conductive feature in the opening through the dielectric layer.
-20. (canceled)
A method comprising:
- forming an adhesion layer over a substrate, wherein forming the adhesion layer uses a first ratio of a first flow rate of an mDEOS precursor gas to a second flow rate of an oxygen precursor gas;
- forming a dielectric layer over a substrate, wherein forming the dielectric layer uses a second ratio of a third flow rate of the mDEOS precursor gas to a fourth flow rate of the oxygen precursor gas, wherein the second ratio is greater than the first ratio;
- forming an opening through the dielectric layer using a plasma etch process, wherein after the plasma etch process, a carbon concentration is substantially uniform;
- and
- forming a conductive feature in the opening through the dielectric layer.
Dependencies are inferred from the claim text.