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US 2015/0087154 A1Published application
High aspect ratio etch with combination mask
AssigneeLam Research Corporation
InventorsJoydeep GUHA, Sirish K. REDDY, Kaushik CHATTOPADHYAY, Thomas W. MOUNTSIER, Aaron EPPLER, Thorsten LILL, Vahid VAHEDI, Harmeet SINGH
Life of this patent
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Abstract
A method for etching features in a stack is provided. A combination hardmask is formed by forming a first hardmask layer comprising carbon or silicon oxide over the stack, forming a second hardmask layer comprising metal over the first hardmask layer, and patterning the first and second hardmask layers. The stack is etched through the combination hardmask.
Claims19
A method for etching features in a stack, comprising:
- forming a combination hardmask, comprising;
- forming a first hardmask layer comprising carbon or silicon oxide over the stack;
- forming a second hardmask layer comprising metal over the first hardmask layer;
- forming a third hardmask layer comprising carbon or silicon oxide over the second hardmask layer, and
- forming a fourth hardmask layer comprising metal over the third hardmask layer;
- etching the fourth hardmask layer, comprising:
- flowing a fourth hardmask layer etch gas comprising a halogen component;
- and
- forming the fourth hardmask layer etch gas into a plasma;
- and
- stopping the flow of the fourth;
- and
- etching the third hardmask layer, comprising:
- flowing a third hardmask layer etch gas comprising oxygen and at least one of COS or SO2;
- forming the first hardmask layer etch gas into a plasma;
- and
- stopping the flow of the first hardmask layer etch gas;
- patterning the first and second hardmask layers;
- and
- etching the stack through the combination hardmask.
17 more elements
(canceled)
A method for etching features in a stack, wherein the stack is at least one of a silicon oxide layer, OPOP or ONON, comprising:
- forming a combination hardmask, comprising;
- forming a first hardmask layer comprising carbon or silicon oxide over the stack;
- forming a second hardmask layer comprising metal over the first hardmask layer, wherein the second hardmask layer comprises at least one of elemental metal, a metal alloy, a metal oxide, metal carbide, or a metal nitride;
- forming a third hardmask layer comprising carbon or silicon oxide over the second hardmask layer;
- forming a fourth hardmask layer comprising metal over the third hardmask layer;
- forming a patterned mask over the hardmask layers;
- etching the fourth hardmask layer through the patterned mask, comprising:
- flowing a fourth hardmask layer etch gas comprising a halogen component;
- and
- forming the fourth hardmask layer etch gas into a plasma, and
- stopping the flow of the fourth;
- and
- etching the third hardmask layer, comprising:
- flowing a third hardmask layer etch gas comprising oxygen and at least one of COS or SO2;
- forming the first hardmask layer etch gas into a plasma;
- and
- stopping the flow of the first hardmask layer etch gas;
- and
- patterning the first and second hardmask layers, wherein the patterning the first and second hardmask layers comprises:
- etching the second hardmask layer, comprising
- flowing a second hardmask layer etch gas comprising a halogen component;
- forming the second hardmask layer etch gas into a plasma;
- and
- stopping the flow of the second hardmask layer etch gas;
- and
- etching the first hardmask layer, comprising;
- flowing a first hardmask layer etch gas comprising oxygen and at least one of COS or SO2;
- forming the first hardmask layer etch gas into a plasma;
- and
- stopping the flow of the first hardmask layer etch gas;
- etching the stack through the combination hardmask.
28 more elements
(canceled)
(canceled)
A method for etching features in a stack, comprising:
- forming a combination hardmask, comprising;
- forming a first hardmask layer comprising carbon or silicon oxide over the stack;
- forming a second hardmask layer comprising metal over the first hardmask layer;
- and
- forming a patterned mask over the second hardmask layer;
- etching the second hardmask layer through the patterned mask, comprising:
- flowing a second hardmask layer etch gas comprising a halogen component;
- forming the second hardmask layer etch gas into a plasma;
- and
- stopping the flow of the second hardmask layer etch gas;
- etching the first hardmask layer, comprising:
- flowing a first hardmask layer etch gas comprising oxygen and at least one of COS or SO2;
- forming the first hardmask layer etch gas into a plasma;
- and
- stopping the flow of the first hardmask layer etch gas;
- and
- etching the stack through the combination hardmask.
14 more elements
Dependencies are inferred from the claim text.