Deep trench etching using HDP chamber
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsFa-Yuan Chang, Buh-Kuan Fang, Shih-Feng Chen, Cheng-Cheng Chang
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Abstract
A process for etching deep trenches in a substrate for purposes such as the fabrication of microelectromechanical systems (MEMS), for example, on the substrate. The two-step process includes first etching a tapered trench having a tapered profile and enhanced sidewall passivation in a substrate along a protective mask which defines the desired trench profile on the substrate surface. Next, the tapered trench is trimmed by high-density plasma in an isotropic etching step to provide a straight-profile deep trench with minimum sidewall passivation.
Claims20
A process for forming a deep trench in a substrate, comprising the steps of:
- providing an etch chamber;
- placing said substrate in said etch chamber;
- etching a tapered trench in said substrate by subjecting said substrate to a first etching step;
- and
- etching said tapered trench to form said deep trench by subjecting said substrate to a second etching step.
A process for forming a deep trench in a substrate, comprising the steps of:
- providing an etch chamber having a cathode and a chamber wall;
- placing said substrate in said etch chamber;
- maintaining said cathode at a temperature of about 10˜45 degrees C. and said chamber wall at a temperature of about 50˜100 degrees C.;
- etching a tapered trench in said substrate by subjecting said substrate to a first etching step;
- and
- etching said tapered trench to form said deep trench by subjecting said substrate to a second etching step.
A process for forming a deep trench in a substrate, comprising the steps of:
- providing a high density plasma etch chamber having a cathode and a chamber wall;
- placing said substrate in said etch chamber;
- etching a tapered trench in said substrate by subjecting said substrate to a first etching step;
- and
- etching said tapered trench to form said deep trench by subjecting said substrate to a second etching step.
Dependencies are inferred from the claim text.