Applied Materials, Inc.

Jie Liu

Nitin K Ingle

Anchuan Wang

Xikun Wang

Jeffrey W Anthis

Benjamin Schmiege

Seung H Park

Zhenjiang Cui

Srinivas D Nemani

Mikhail Korolik

Jingchun Zhang

David Benjaminson

Zhijun Chen

Ching-Mei Hsu

Vinod Robert Purayath

Sang-Jin Kim

Mandar Balasaheb Pandit

Hanshen Zhang

Linlin Wang

Xing Zhong

A method for processing a semiconductor substrate is described herein. The method described herein includes generating fluorine radicals and ions, delivering the fluorine radicals through an ion blocker to a processing region, and removing one or more portions of a gate structure to expose one or more portions of a gate dielectric material disposed thereunder. The gate structure includes at least two ceramic or metal layers, and the gate dielectric material is made of a high-k dielectric material. A substrate having the gate structure and gate dielectric material formed thereon is disposed in the processing region, and the temperature of the substrate is maintained at about 60 degrees Celsius or higher. By etching the gate structure using fluorine radicals at a temperature greater or equal to 60 degrees Celsius, the at least two ceramic or metal layers have a flat cross sectional profile.

HKMG integration

Methods are described herein for etching metal films which are difficult to volatize. The methods include exposing a metal film to a chlorine-containing precursor (e.g. Cl). Chlorine is then removed from the substrate processing region. A carbon-and-nitrogen-containing precursor (e.g. TMEDA) is delivered to the substrate processing region to form volatile metal complexes which desorb from the surface of the metal film. The methods presented remove metal while very slowly removing the other exposed materials. A thin metal oxide layer may be present on the surface of the metal layer, in which case a local plasma from hydrogen may be used to remove the oxygen or amorphize the near surface region, which has been found to increase the overall etch rate.

Oxide and metal removal

Provided are methods for etching films comprising transition metals which help to minimize higher etch rates at the grain boundaries of polycrystalline materials. Certain methods pertain to amorphization of the polycrystalline material, other pertain to plasma treatments, and yet other pertain to the use of small doses of halide transfer agents in the etch process.

Methods of etching films with reduced surface roughness

In one implementation, a method of removing a metal-containing layer is provided. The method comprises generating a plasma from a fluorine-containing gas. The plasma comprises fluorine radicals and fluorine ions. The fluorine ions are removed from the plasma to provide a reactive gas having a higher concentration of fluorine radicals than fluorine ions. A substrate comprising a metal-containing layer is exposed to the reactive gas. The reactive gas dopes at least a portion of the metal-containing layer to form a metal-containing layer doped with fluorine radicals. The metal-containing layer doped with fluorine radicals is exposed to a nitrogen and hydrogen containing gas mixture and the reactive gas to remove at least a portion of the metal-containing layer doped with fluorine radicals.

Two-step fluorine radical etch of hafnium oxide

A method of removing an amorphous silicon/silicon oxide film stack from vias is described. The method may involve a remote plasma comprising fluorine and a local plasma comprising fluorine and a nitrogen-and-hydrogen-containing precursor unexcited in the remote plasma to remove the silicon oxide. The method may then involve a local plasma of inert species to potentially remove any thin carbon layer (leftover from the photoresist) and to treat the amorphous silicon layer in preparation for removal. The method may then involve removal of the treated amorphous silicon layer with several options possibly within the same substrate processing region. The bottom of the vias may then possess exposed single crystal silicon which is conducive to epitaxial single crystal silicon film growth. The methods presented herein may be particularly well suited for 3d NAND (e.g. VNAND) device formation.

Cleaning high aspect ratio vias

Methods of selectively etching silicon relative to silicon germanium are described. The methods include a remote plasma etch using plasma effluents formed from a fluorine-containing precursor and a hydrogen-containing precursor. Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents react with the silicon. The plasmas effluents react with exposed surfaces and selectively remove silicon while very slowly removing other exposed materials. The methods are useful for removing SiGefaster than SiGe, for X&#x3c;Y. In some embodiments, the silicon germanium etch selectivity results partly from the presence of an ion suppression element positioned between the remote plasma and the substrate processing region.

Etch suppression with germanium

Methods of selectively etching tungsten from the surface of a patterned substrate are described. The etch electrically separates vertically arranged tungsten slabs from one another as needed, for example, in the manufacture of vertical flash memory devices. The tungsten etch may selectively remove tungsten relative to films such as silicon, polysilicon, silicon oxide, aluminum oxide, titanium nitride and silicon nitride. The methods include exposing electrically-shorted tungsten slabs to remotely-excited fluorine formed in a capacitively-excited chamber plasma region. The methods then include exposing the tungsten slabs to remotely-excited fluorine formed in an inductively-excited remote plasma system. A low electron temperature is maintained in the substrate processing region during each operation to achieve high etch selectivity.

Tungsten separation

A method of removing titanium nitride hardmask is described. The hardmask resides above a low-k dielectric layer prior to removal and the low-k dielectric layer retains a relatively low net dielectric constant after the removal process. The low-k dielectric layer may be part of a dual damascene structure having copper at the bottom of the vias. A non-porous carbon layer is deposited prior to the titanium nitride hardmask removal to protect the low-k dielectric layer and the copper. The titanium nitride hardmask is removed with a gas-phase etch using plasma effluents formed in a remote plasma from a chlorine-containing precursor. Plasma effluents within the remote plasma are flowed into a substrate processing region where the plasma effluents react with the titanium nitride.

Chlorine-based hardmask removal

Methods of etching exposed titanium nitride with respect to other materials on patterned heterogeneous structures are described, and may include a remote plasma etch formed from a fluorine-containing precursor. Precursor combinations including plasma effluents from the remote plasma are flowed into a substrate processing region to etch the patterned structures with high titanium nitride selectivity under a variety of operating conditions. The methods may be used to remove titanium nitride at faster rates than a variety of metal, nitride, and oxide compounds.

Selective titanium nitride etching

Methods of selectively etching tungsten from the surface of a patterned substrate are described. The methods electrically separate vertically arranged tungsten slabs from one another as needed. The vertically arranged tungsten slabs may form the walls of a trench during manufacture of a vertical flash memory cell. The tungsten etch may selectively remove tungsten relative to films such as silicon, polysilicon, silicon oxide, aluminum oxide, titanium nitride and silicon nitride. The methods include exposing electrically-shorted tungsten slabs to remotely-excited fluorine formed in a remote plasma region. Process parameters are provided which result in uniform tungsten recess within the trench. A low electron temperature is maintained in the substrate processing region to achieve high etch selectivity and uniform removal throughout the trench.

Vertical gate separation

Methods of evenly etching tungsten liners from high aspect ratio trenches are described. The methods include a remote plasma etch using plasma effluents formed from a fluorine-containing precursor and a high flow of helium. Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents react with tungsten coating a patterned substrate having high aspect ratio trenches. The plasmas effluents react with exposed surfaces and evenly remove tungsten from outside the trenches and on the sidewalls of the trenches. The plasma effluents pass through an ion suppression element positioned between the remote plasma and the substrate processing region. Optionally, the methods may include concurrent ion bombardment of the patterned substrate to help remove potentially thicker horizontal tungsten regions, e.g., at the bottom of the trenches or between trenches.

Gas-phase tungsten etch

Methods of evenly etching tungsten liners from high aspect ratio trenches are described. The methods include ion bombardment of a patterned substrate having high aspect ratio trenches. The ion bombardment includes fluorine-containing ions and the ion bombardment may be stopped before breaking through the horizontal liner portion outside the trenches but near the opening of the trenches. The methods then include a remote plasma etch using plasma effluents formed from a fluorine-containing precursor. Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents react with the tungsten. The plasmas effluents react with exposed surfaces and remove tungsten from outside the trenches and on the sidewalls of the trenches. The plasma effluents pass through an ion suppression element positioned between the remote plasma and the substrate processing region.

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Sunnyvale, CA, United States of America

Jie Liu