Lam Research Corporation

Kyeong-Koo Chi

Erik A Edelberg

Jonathan Sungehul Kim

Joseph James Vegh

Sanghyuk Choi

In accordance with this disclosure, there is provided several inventions, including a method for etching a plurality of features in a stack comprising alternating layers above a substrate, comprising: providing a steady state flow of an etching gas, wherein the etching gas comprises: a molecule A comprising sulfur and fluorine; a molecule B comprising carbon, fluorine, and hydrogen; and a molecule C comprising carbon and fluorine and not hydrogen; forming the etching gas into a plasma; and etching the features into the stack through the plurality of alternating layers.

Sulfur and fluorine containing etch chemistry for improvement of distortion and bow control for har etch

A method for etching an ultra high aspect ratio feature in a dielectric layer through a carbon based mask is provided. The dielectric layer is selectively etched 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. The selective etch is stopped. The fluorocarbon polymer is selectively removed with respect to the carbon based mask, so that the carbon based mask remains, using a trimming. The selectively removing the fluorocarbon polymer is stopped. The dielectric layer is again selectively etched with respect to the carbon based mask, wherein the second selectively etching provides a net deposition of a fluorocarbon based polymer on the carbon based mask.

Ultra-high aspect ratio dielectric etch

A method for etching a dielectric layer is provided. The dielectric layer is disposed over a substrate and below a patterned mask having a line-space pattern. The method includes (a) providing an etchant gas comprising CF4, COS, and an oxygen containing gas, (b) forming a plasma from the etchant gas, and (c) etching the dielectric layer into the line-space pattern through the mask with the plasma from the etchant gas. The gas flow rate of CF4 may have a ratio greater than 50% of a total gas flow rate of all reactive gas components. The gas flow rate of COS may be between 1% and 50%. The method reduces bowing in etching of the dielectric layer by adding COS to the etchant gas.

Profile control in dielectric etch

A method for etching a line pattern in an etch layer disposed below an antireflective coating (ARC) layer below a patterned mask is provided. The method includes opening the ARC layer, in which an ARC opening gas comprising CF3I, a fluorocarbon (including hydrofluorocarbon) containing gas, and an oxygen containing gas are provided, a plasma is formed from the ARC opening gas to open the ARC layer, and providing the ARC opening gas is stopped. Line pattern features are etched into the etch layer through the opened ARC layer.

CD bias loading control with ARC layer open

To achieve the foregoing and in accordance with the purpose of the present invention a method for etching an etch layer disposed below an antireflective coating (ARC) layer below a patterned mask is provided. The ARC layer is opened, and features are etched into the etch layer through the patterned mask. The opening the ARC layer includes (1) providing an ARC opening gas comprising a halogen containing gas, COS, and an oxygen containing gas, (2) forming a plasma from the ARC opening gas to open the ARC layer, and (3) stopping providing the ARC opening gas to stop the plasma. The patterned mask may be a photoresist (PR) mask having a line-space pattern. COS in the ARC opening gas reduces line width roughness (LWR) of the patterned features of the etch layer.

Line width roughness control with arc layer open

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.

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San Jose, CA, United States of America

Kyeong-Koo Chi