Process for etching silicon dioxide layer without micro masking effect
AssigneeIntel Corporation
InventorsHongging Shan, Donald W. Jillie, Jr.
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Abstract
A process for etching a silicon dioxide layer is disclosed. The novel two step etch process is used, for example, to perform a contact etch through a BPSG layer. Both etch steps are carried out in a flow of O.sub.2 and CHF.sub.3. In the first step, a high flow rate of oxygen (approximately 19 SCCM) is used. During this step, the bulk of the oxide is removed, without the problem of micro masking wherein small localized regions remain partially un-etched. In the second step, the remaining oxide is removed in a lower O.sub.2 flow rate, giving good oxide to silicon selectivity.
Claims28
A process for etching an oxide layer during the fabrication of a device on a semiconductor substrate comprising the steps of:
- providing said semiconductor substrate having said oxide layer;
- and
- performing an etch in a flow of a mixture of gases comprising a halogen containing species and O.sub.2, wherein said flow of said O.sub.2 is equal to or greater than 15 SCCM and wherein said flow of said O.sub.2 is equal to or greater than 10% by volume of the total gas flow.
A process for etching an oxide layer during the fabrication of a device on a semiconductor substrate comprising the steps of:
- providing said semiconductor substrate having said oxide layer;
- performing a first etch in a first flow of a first mixture of gases comprising a first halogen containing species and O.sub.2 ;
- and
- performing a second etch in a second flow of a second mixture of gases comprising a second halogen containing species and O.sub.2, wherein said flow of said O.sub.2 in said first mixture is greater than said flow of said O.sub.2 in said second mixture.
A process for forming a contact opening through an oxide layer during the fabrication of a device on a semiconductor substrate, comprising the steps of:
- providing said substrate with said oxide layer;
- forming a mask on said substrate to expose said oxide layer in regions where said contact opening is to be formed;
- performing a first etch in a flow of a first mixture of gases comprising a first halogen containing species and O.sub.2 ;
- performing a second etch in a flow of a second mixture of gases comprising a second halogen containing species and O.sub.2 wherein said flow of said O.sub.2 in said first mixture is greater than said flow of said O.sub.2 in said second mixture;
- and
- removing said mask.
Dependencies are inferred from the claim text.