Pulsed ultra-high aspect ratio dielectric etch
AssigneeLam Research Corporation
InventorsKyeong-Koo Chi, Erik A. Edelberg
Life of this patent
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Abstract
A method for selectively etching an ultra high aspect ratio feature dielectric layer through a carbon based mask in an etch chamber is provided. A flow of an etch gas is provided, comprising a fluorocarbon containing molecule and an oxygen containing molecule to the etch chamber. A pulsed bias RF signal is provided. An energizing RF signal is provided to transform the etch gas to a plasma.
Claims19
A method for etching an ultra high aspect ratio feature dielectric layer through a carbon based mask in an etch chamber, comprising:
- a selective etching the dielectric layer with respect to the carbon based mask, wherein the selective etching provides a net deposition of a fluorocarbon based polymer on the carbon based mask;
- stopping the selective etch;
- and
- a subsequent selective etching the dielectric layer with respect to the carbon based mask, comprising:
- providing a flow of an etch gas, comprising a fluorocarbon containing molecule and an oxygen containing molecule to the etch chamber;
- providing a pulsed bias RF signal;
- and
- providing an energizing RF signal.
A method for selectively etching an ultra high aspect ratio feature dielectric layer through a carbon based mask in an etch chamber, comprising:
- providing a flow of an etch gas, comprising a fluorocarbon containing molecule and an oxygen containing molecule to the etch chamber;
- providing a pulsed bias RF signal;
- and
- providing an energizing RF signal to transform the etch gas to a plasma.
An apparatus for etching UHAR features in an etch layer below an carbon based mask, comprising:
- a plasma processing chamber, comprising:
- a chamber wall forming a plasma processing chamber enclosure;
- a substrate support for supporting a substrate within the plasma processing chamber enclosure;
- a pressure regulator for regulating the pressure in the plasma processing chamber enclosure;
- at least one electrode for providing power to the plasma processing chamber enclosure for sustaining a plasma;
- an RF bias source providing a signal with a RF frequency between 1 kHz and 10 MHZ;
- a pulse generation device that is able to pulse the RF bias source, connected to the RF bias source;
- a first RF excitation source providing a signal with a RF frequency between 1 MHz and 5 MHz;
- a second RF excitation source providing a signal with a RF frequency between 10 MHz and 40 MHz;
- a gas inlet for providing gas into the plasma processing chamber enclosure;
- and
- a gas outlet for exhausting gas from the plasma processing chamber enclosure;
- a gas source in fluid connection with the gas inlet, comprising:
- an oxygen source;
- and
- a fluorocarbon polymer gas source;
- and
- a controller controllably connected to the gas source, the RF bias source, the first RF excitation source, and the second RF excitation source and the at least one electrode, comprising:
- at least one processor;
- and
- computer readable media, comprising computer readable code for providing a selective etch of the dielectric layer with respect to the carbon based mask, where the first selective etch provides a net deposition of a fluorocarbon based polymer, comprising:
- computer readable code for providing a flow of an etch gas comprising oxygen from the oxygen source and a fluorocarbon polymer gas from the fluorocarbon polymer gas source to the processing chamber enclosure;
- computer readable code for energizing the RF bias source;
- computer readable code for pulsing the RF bias source;
- and
- computer readable code for energizing the first RF excitation source and the second RF excitation source to provide energy, to form a plasma from the etch gas and polymer forming gas.
Dependencies are inferred from the claim text.