Self limiting lateral atomic layer etch
First Claim
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1. An apparatus for processing a substrate, the apparatus comprising:
- a process chamber;
a gas box having a plurality of first outlets and a second outlet that are both fluidly connected with the process chamber via a plurality of top inlets and a side inlet;
a mixing chamber for mixing ammonia with one or more of the process gases, the mixing chamber separate from the gas box, fluidly connected to the plurality of first outlets, fluidly connected with the plurality of top inlets and the side inlet, and fluidly interposed between the first outlet, and the plurality of top inlets and the side inlet such that;
gas is configured to flow from the plurality of first outlets, through the mixing chamber, and to the plurality of top inlets and the side inlet, andgas is configured to flow from the second outlet and to the plurality of top inlets and the side inlet without flowing through the mixing chamber;
a first set of parallel valves fluidly interposed between the mixing chamber, and the plurality of top inlets and the side inlet, and configured to control the flow of gas between the mixing chamber and the plurality of top inlets and the side inlet;
a second set of parallel valves fluidly interposed between the second outlet, and the plurality of top inlets and the side inlet, and configured to control the flow of gas between the second outlet and the plurality of top inlets and the side inlet;
a first gas source in the gas box comprising an oxidant and fluidly connected to one of the first outlets;
a second gas source in the gas box comprising a fluorine-containing etchant and fluidly connected to another one of the first outlets;
a heater configured to heat a substrate in the process chamber; and
a controller having at least one processor and a memory, wherein;
the at least one processor and the memory are communicatively connected with one another,the memory stores non-transient, computer-executable instructions for controlling the at least one processor to control the gas box, the first set of parallel valves, and the second set of parallel valves to;
(i) cause the oxidant gas to flow to the process chamber housing a substrate to conformally oxidize surface of a feature in a semiconductor layer of the substrate to form an oxidized surface,(ii) cause, after (i), the fluorine-containing etchant gas to flow to the process chamber housing the substrate to expose the substrate to the fluorine-containing etchant gas to isotropically etch the oxidized surface of the substrate in a self-limiting reaction selective to non-oxidized semiconductor material,(iii) cause, after (ii), the heater to heat the substrate to remove non-volatile solid etch byproducts by sublimation, and(iv) repeat (i), (ii), and (iii).
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Abstract
Methods of and apparatuses for laterally etching semiconductor substrates using an atomic layer etch process involving exposing an oxidized surface of a semiconductor substrate to a fluorine-containing etch gas and heating the substrate to remove non-volatile etch byproducts by a sublimation mechanism are provided herein. Methods also including additionally pulsing a hydrogen-containing gas when pulsing the fluorine-containing etch gas. Apparatuses also include an ammonia mixing manifold suitable for separately preparing and mixing ammonia for use in various tools.
44 Citations
16 Claims
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1. An apparatus for processing a substrate, the apparatus comprising:
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a process chamber; a gas box having a plurality of first outlets and a second outlet that are both fluidly connected with the process chamber via a plurality of top inlets and a side inlet; a mixing chamber for mixing ammonia with one or more of the process gases, the mixing chamber separate from the gas box, fluidly connected to the plurality of first outlets, fluidly connected with the plurality of top inlets and the side inlet, and fluidly interposed between the first outlet, and the plurality of top inlets and the side inlet such that; gas is configured to flow from the plurality of first outlets, through the mixing chamber, and to the plurality of top inlets and the side inlet, and gas is configured to flow from the second outlet and to the plurality of top inlets and the side inlet without flowing through the mixing chamber; a first set of parallel valves fluidly interposed between the mixing chamber, and the plurality of top inlets and the side inlet, and configured to control the flow of gas between the mixing chamber and the plurality of top inlets and the side inlet; a second set of parallel valves fluidly interposed between the second outlet, and the plurality of top inlets and the side inlet, and configured to control the flow of gas between the second outlet and the plurality of top inlets and the side inlet; a first gas source in the gas box comprising an oxidant and fluidly connected to one of the first outlets; a second gas source in the gas box comprising a fluorine-containing etchant and fluidly connected to another one of the first outlets; a heater configured to heat a substrate in the process chamber; and a controller having at least one processor and a memory, wherein; the at least one processor and the memory are communicatively connected with one another, the memory stores non-transient, computer-executable instructions for controlling the at least one processor to control the gas box, the first set of parallel valves, and the second set of parallel valves to; (i) cause the oxidant gas to flow to the process chamber housing a substrate to conformally oxidize surface of a feature in a semiconductor layer of the substrate to form an oxidized surface, (ii) cause, after (i), the fluorine-containing etchant gas to flow to the process chamber housing the substrate to expose the substrate to the fluorine-containing etchant gas to isotropically etch the oxidized surface of the substrate in a self-limiting reaction selective to non-oxidized semiconductor material, (iii) cause, after (ii), the heater to heat the substrate to remove non-volatile solid etch byproducts by sublimation, and (iv) repeat (i), (ii), and (iii). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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Specification