Apparatus and methods for selectively etching silicon oxide films
AssigneeASM IP Holding B.V.
InventorsFei Wang, Woo Jung Shin
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Abstract
An apparatus and methods for selectively etching a particular layer are disclosed. The apparatus and methods are directed towards maintaining the etch rate of the particular layer, while keeping intact a non-etched layer. A gas mixture may be flowed onto the substrate in separate loops having an oxide layer and an oxynitride layer as an etch layer and a nitride layer as a non-etched layer, for example. A reaction between the resulting gas mixture and the particular layer takes place, resulting in etching of the oxide layer and the oxynitride layer while maintaining the nitride layer in the above example.
Claims12
A system for selectively etching a film disposed on a substrate, the system comprising:
- a reaction chamber configured to process a substrate, wherein the substrate has an oxide layer, a nitride layer, and an oxynitride layer disposed thereon;
- a remote plasma unit coupled to the reaction chamber;
- a fluorine precursor source configured to provide a fluorine precursor gas to the reaction chamber, the fluorine precursor gas comprising at least one of:
- nitrogen trifluoride (NF3);
- carbon tetrafluoride (CF4);
- sulfur hexafluoride (SF6);
- hydrogen fluoride (HF);
- hydrofluoric acid (HF) with water vapor;
- or fluorine (F2);
- a hydrogen precursor source configured to provide a hydrogen precursor gas to the reaction chamber, the hydrogen precursor gas comprising at least one of:
- ammonia (NH3);
- hydrazine (N2H4);
- urea (NH2CONH2);
- hydrogen (H2);
- an alcohol;
- or an acidic gas;
- and
- an inert gas source configured to provide an inert gas, wherein the inert gas comprises at least one of:
- argon;
- krypton;
- helium;
- xenon;
- or nitrogen,
- wherein the remote plasma unit is disposed fluidly between the fluorine precursor source and the reaction chamber, and between the inert gas source and the reaction chamber, and configured to provide radicals of the fluorine precursor gas and the inert gas,
- wherein the hydrogen precursor source is fluidly coupled between the remote plasma unit and the reaction chamber, such that the remote plasma unit provides the radicals of the fluorine precursor gas and the inert gas prior to being combined with the hydrogen precursor gas;
- wherein the system is configured to flow a gaseous mixture of the fluorine precursor gas, the hydrogen precursor gas, and the inert gas onto the substrate, resulting in an etching of the oxide layer and the oxynitride layer while maintaining the nitride layer substantially intact.
Dependencies are inferred from the claim text.