Method for backside polymer reduction in dry-etch process
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsHuang-Ming Chen, Chun-Li Chou, Chao-Cheng Chen, Hun-Jan Tao
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Abstract
A method for preventing the formation of contaminating polymeric films on the backsides of semiconductor substrates includes providing an oxygen-impregnated focus ring and/or an oxygen-impregnated chuck that releases oxygen during etching operations. The method further provides delivering oxygen gas to the substrate by mixing oxygen in the cooling gas mixture, maintaining the focus ring at a temperature no greater than the substrate temperature during etching and cleaning the substrate using a two step plasma cleaning sequence that includes suspending the substrate above the chuck.
Claims19
A method for etching a substrate comprising:
- providing an etching apparatus including an etching chamber having therein a chuck and a focus ring;
- etching a film on a substrate disposed on said chuck;
- and
- maintaining said focus ring at a temperature less than a temperature of said substrate and maintaining at least a portion of said focus ring in direct contact with said chuck, during said etching.
A method for etching a substrate comprising:
- providing a substrate on a chuck peripherally surrounded by a focus ring that includes a portion that extends inwardly beneath a peripheral edge of said chuck that is disposed directly underneath a peripheral portion of said substrate;
- etching said substrate;
- generating an oxygen plasma and performing a clean operation while said substrate is on said chuck;
- and
- further generating a further oxygen plasma and performing a further clean operation while said substrate is positioned above said chuck or a further chuck.
A method for etching a semiconductor substrate comprising:
- providing an etching tool having an etch chamber including a semiconductor substrate disposed on a chuck and substantially peripherally surrounded by a focus ring that includes oxygen therein;
- performing an etching operation such that said oxygen is liberated;
- during said performing, maintaining said focus ring at a temperature less than a temperature of said semiconductor substrate and at least partially in contact with said chuck;
- after said performing, generating an oxygen plasma and cleaning said semiconductor substrate with said oxygen plasma while said semiconductor substrate is disposed on said chuck;
- after said performing, generating a further oxygen plasma and further cleaning said semiconductor substrate with said further oxygen plasma while said semiconductor substrate is spaced over said chuck or a further chuck;
- and
- cooling by directing a mixture of helium and oxygen through openings formed in said chuck or said further chuck.
Dependencies are inferred from the claim text.