Abstract: Methods of selectively etching metal-containing materials from the surface of a substrate are described. The etch selectively removes metal-containing materials relative to silicon-containing films such as silicon, polysilicon, silicon oxide, silicon germanium, silicon carbide, silicon carbon nitride and/or silicon nitride. The methods include exposing metal-containing materials to halogen containing species in a substrate processing region. No plasma excites the halogen-containing precursor either remotely or locally in embodiments.

Abstract: 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.

Abstract: Methods of selectively etching tungsten relative to silicon-containing films (e.g. silicon oxide, silicon carbon nitride and (poly)silicon) as well as tungsten oxide are described. The methods include a remote plasma etch formed from a fluorine-containing precursor and/or hydrogen (H2). Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents react with the tungsten. The plasma effluents react with exposed surfaces and selectively remove tungsten while very slowly removing other exposed materials. Sequential and simultaneous methods are included to remove thin tungsten oxide which may, for example, result from exposure to the atmosphere.

Abstract: 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. Cl2). 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.

Abstract: 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.

Abstract: 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 and the non-porous carbon layer are 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 non-porous carbon layer and the titanium nitride.

Abstract: 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 fluorine-containing precursor. Plasma effluents within the remote plasma are flowed into a substrate processing region where the plasma effluents react with the titanium nitride.

Abstract: Methods of producing V-shaped trenches in crystalline substrates are described. The methods involve processing a patterned substrate with etch masking materials defining each side of exposed silicon (100). The exposed silicon (100) is exposed to remotely-excited halogen-containing precursor including chlorine or bromine. The plasma effluents formed from the halogen-containing precursor preferentially remove silicon from all exposed facets other than silicon (111). Etching the crystalline substrates with the plasma effluents produce at least two silicon (111) facets between two adjacent masking elements. Forming the silicon (111) facets may be accelerated by pretreating the crystalline substrates using a halogen-containing precursor locally excited in a biased plasma to initiate the generation of the trench.

Abstract: Methods of selectively etching metal-containing materials from the surface of a substrate are described. The etch selectively removes metal-containing materials relative to silicon-containing films such as silicon, polysilicon, silicon oxide, silicon germanium and/or silicon nitride. The methods include exposing metal-containing materials to halogen containing species in a substrate processing region. A remote plasma is used to excite the halogen-containing precursor and a local plasma may be used in embodiments. Metal-containing materials on the substrate may be pretreated using moisture or another OH-containing precursor before exposing the resulting surface to remote plasma excited halogen effluents in embodiments.

Abstract: 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. Cl2). 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.

Abstract: Methods of selectively etching aluminum oxide from the surface of a patterned substrate are described. The etch selectively removes aluminum oxide relative to other metal oxides and silicon-containing films such as silicon, polysilicon, silicon oxide, silicon germanium and/or silicon nitride. The methods include exposing aluminum oxide to plasma effluents formed in a remote plasma from a chlorine-containing precursor and a hydrocarbon. A remote plasma is used to excite the precursors and a local plasma is used to further excite the plasma effluents and accelerate ions toward the patterned substrate.

Abstract: 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.

Abstract: Methods of selectively etching metal-containing materials from the surface of a substrate are described. The etch selectively removes metal-containing materials relative to silicon-containing films such as silicon, polysilicon, silicon oxide, silicon germanium and/or silicon nitride. The methods include exposing metal-containing materials to halogen containing species in a substrate processing region. A remote plasma is used to excite the halogen-containing precursor and a local plasma may be used in embodiments. Metal-containing materials on the substrate may be pretreated using moisture or another OH-containing precursor before exposing the resulting surface to remote plasma excited halogen effluents in embodiments.

Abstract: 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 fluorine-containing precursor. Plasma effluents within the remote plasma are flowed into a substrate processing region where the plasma effluents react with the titanium nitride.

Abstract: 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.

Abstract: Methods of producing V-shaped trenches in crystalline substrates are described. The methods involve processing a patterned substrate with etch masking materials defining each side of exposed silicon (100). The exposed silicon (100) is exposed to remotely-excited halogen-containing precursor including chlorine or bromine. The plasma effluents formed from the halogen-containing precursor preferentially remove silicon from all exposed facets other than silicon (111). Etching the crystalline substrates with the plasma effluents produce at least two silicon (111) facets between two adjacent masking elements. Forming the silicon (111) facets may be accelerated by pretreating the crystalline substrates using a halogen-containing precursor locally excited in a biased plasma to initiate the generation of the trench.

Abstract: Methods of selectively etching titanium oxide relative to silicon oxide, silicon nitride and/or other dielectrics are described. The methods include a remote plasma etch using plasma effluents formed from a fluorine-containing precursor and/or a chlorine-containing precursor. Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents react with the titanium oxide. The plasmas effluents react with exposed surfaces and selectively remove titanium oxide while very slowly removing other exposed materials. A direction sputtering pretreatment is performed prior to the remote plasma etch and enables an increased selectivity as well as a directional selectivity. In some embodiments, the titanium oxide etch selectivity results partly from the presence of an ion suppression element positioned between the remote plasma and the substrate processing region.

Abstract: 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.

Abstract: 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.

Abstract: Methods are described herein for selectively etching titanium nitride relative to dielectric films, which may include, for example, alternative metals and metal oxides lacking in titanium and/or silicon-containing films (e.g. silicon oxide, silicon carbon nitride and low-K dielectric films). The methods include a remote plasma etch formed from a chlorine-containing precursor. Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents react with the titanium nitride. The plasma effluents react with exposed surfaces and selectively remove titanium nitride while very slowly removing the other exposed materials. The substrate processing region may also contain a plasma to facilitate breaking through any titanium oxide layer present on the titanium nitride. The plasma in the substrate processing region may be gently biased relative to the substrate to enhance removal rate of the titanium oxide layer.