Abstract: Methods of forming air gaps in a 3-d flash memory cell using only gas-phase etching techniques are described. The methods include selectively gas-phase etching tungsten deposited into the stack structure to separate the tungsten levels. Other metals than tungsten may be used. The methods also include selectively etching silicon oxide from between the tungsten levels to make room for vertically spaced air gaps. A nonconformal silicon oxide layer is then deposited to trap the air gaps. Both tungsten removal and silicon oxide removal use remotely excited fluorine-containing apparatuses attached to the same mainframe to facilitate performing both operations without an intervening atmospheric exposure. The nonconformal silicon oxide may be deposited inside or outside the mainframe.

Abstract: Methods of forming flash memory cells are described which incorporate air gaps for improved performance. The methods are useful for so-called “2-d flat cell” flash architectures. 2-d flat cell flash memory involves a reactive ion etch to dig trenches into multi-layers containing high work function and other metal layers. The methods described herein remove the metal oxide debris from the sidewalls of the multi-layer trench and then, without breaking vacuum, selectively remove shallow trench isolation (STI) oxidation which become the air gaps. Both the metal oxide removal and the STI oxidation removal are carried out in the same mainframe with highly selective etch processes using remotely excited fluorine plasma effluents.

Abstract: Methods of etching back shallow trench isolation (STI) dielectric and trimming the exposed floating gate without breaking vacuum are described. The methods include recessing silicon oxide dielectric gapfill to expose vertical sidewalls of polysilicon floating gates. The exposed vertical sidewalls are then isotropically etched to evenly thin the polysilicon floating gates on the same substrate processing mainframe. Both recessing silicon oxide and isotropically etching polysilicon use remotely excited fluorine-containing apparatuses attached to the same mainframe to facilitate performing both operations without an intervening atmospheric exposure. An inter-poly dielectric may then be conformally deposited either on the same mainframe or outside the mainframe.

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: Systems, chambers, and processes are provided for controlling process defects caused by moisture contamination. The systems may provide configurations for chambers to perform multiple operations in a vacuum or controlled environment. The chambers may include configurations to provide additional processing capabilities in combination chamber designs. The methods may provide for the limiting, prevention, and correction of aging defects that may be caused as a result of etching processes performed by system tools.

Abstract: A method of etching exposed silicon-and-carbon-containing material on patterned heterogeneous structures is described and includes a remote plasma etch formed from a fluorine-containing precursor and an oxygen-containing precursor. Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents react with the exposed regions of silicon-and-carbon-containing material. The plasmas effluents react with the patterned heterogeneous structures to selectively remove silicon-and-carbon-containing material from the exposed silicon-and-carbon-containing material regions while very slowly removing other exposed materials. The silicon-and-carbon-containing material selectivity results partly from the presence of an ion suppression element positioned between the remote plasma and the substrate processing region. The ion suppression element reduces or substantially eliminates the number of ionically-charged species that reach the substrate.

Abstract: Methods of selectively etching silicon germanium relative to silicon are described. The methods 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 silicon germanium. The plasmas effluents react with exposed surfaces and selectively remove silicon germanium while very slowly removing other exposed materials. Generally speaking, the methods are useful for removing Si(1-X)GeX (including germanium i.e. X=1) faster than Si(1-Y)GeY, for all X>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.

Abstract: A method of etching silicon nitride on patterned heterogeneous structures is described and includes a gas phase etch using partial remote plasma excitation. The remote plasma excites a fluorine-containing precursor and the plasma effluents created are flowed into a substrate processing region. A hydrogen-containing precursor, e.g. water, is concurrently flowed into the substrate processing region without plasma excitation. The plasma effluents are combined with the unexcited hydrogen-containing precursor in the substrate processing region where the combination reacts with the silicon nitride. The plasmas effluents react with the patterned heterogeneous structures to selectively remove silicon nitride while retaining silicon, such as polysilicon.

Abstract: A method of etching carbon films on patterned heterogeneous structures is described and includes a gas phase etch using remote plasma excitation. The remote plasma excites a fluorine-containing precursor and an oxygen-containing precursor, the plasma effluents created are flowed into a substrate processing region. The plasma effluents etch the carbon film more rapidly than silicon, silicon nitride, silicon carbide, silicon carbon nitride and silicon oxide.

Abstract: A method of etching doped silicon oxide on patterned heterogeneous structures is described and includes a gas phase etch using partial remote plasma excitation. The remote plasma excites a fluorine-containing precursor and the plasma effluents created are flowed into a substrate processing region. A hydrogen-containing precursor, e.g. water, is concurrently flowed into the substrate processing region without plasma excitation. The plasma effluents are combined with the unexcited hydrogen-containing precursor in the substrate processing region where the combination reacts with the doped silicon oxide. The plasmas effluents react with the patterned heterogeneous structures to selectively remove doped silicon oxide.

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.

Abstract: A method of etching exposed titanium oxide on heterogeneous structures is described and includes a remote plasma etch formed from a fluorine-containing precursor. Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents may combine with a nitrogen-containing precursor such as an amine (N:) containing precursor. Reactants thereby produced etch the patterned heterogeneous structures with high titanium oxide selectivity while the substrate is at elevated temperature. Titanium oxide etch may alternatively involve supplying a fluorine-containing precursor and a source of nitrogen-and-hydrogen-containing precursor to the remote plasma. The methods may be used to remove titanium oxide while removing little or no low-K dielectric, polysilicon, silicon nitride or titanium nitride.

Abstract: A method of etching silicon nitride on patterned heterogeneous structures is described and includes a remote plasma etch formed from a fluorine-containing precursor and a nitrogen-and-oxygen-containing precursor. Plasma effluents from two remote plasmas are flowed into a substrate processing region where the plasma effluents react with the silicon nitride. The plasmas effluents react with the patterned heterogeneous structures to selectively remove silicon nitride while very slowly removing silicon, such as polysilicon. The silicon nitride selectivity results partly from the introduction of fluorine-containing precursor and nitrogen-and-oxygen-containing precursor using distinct (but possibly overlapping) plasma pathways which may be in series or in parallel.

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 are described herein for etching metal films, such as cobalt and nickel, 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.

Abstract: A method of etching exposed silicon oxide on patterned heterogeneous structures is described and includes a gas phase etch using plasma effluents formed in a remote plasma. The remote plasma excites a fluorine-containing precursor in combination with an oxygen-containing precursor. Plasma effluents within the remote plasma are flowed into a substrate processing region where the plasma effluents combine with water vapor or an alcohol. The combination react with the patterned heterogeneous structures to remove two separate regions of silicon oxide at distinct etch rates. The methods may be used to remove doped silicon oxide faster than undoped silicon oxide or more lightly-doped silicon oxide. The relative humidity in the substrate processing region may be low during the etch process to increase the etch selectivity of the doped silicon oxide.

Abstract: Systems, chambers, and processes are provided for controlling process defects caused by moisture contamination. The systems may provide configurations for chambers to perform multiple operations in a vacuum or controlled environment. The chambers may include configurations to provide additional processing capabilities in combination chamber designs. The methods may provide for the limiting, prevention, and correction of aging defects that may be caused as a result of etching processes performed by system tools.

Abstract: 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.

Abstract: Systems, chambers, and processes are provided for controlling process defects caused by moisture contamination. The systems may provide configurations for chambers to perform multiple operations in a vacuum or controlled environment. The chambers may include configurations to provide additional processing capabilities in combination chamber designs. The methods may provide for the limiting, prevention, and correction of aging defects that may be caused as a result of etching processes performed by system tools.

Abstract: A method of selectively etching a metal-containing film from a substrate comprising a metal-containing layer and a silicon oxide layer includes flowing a fluorine-containing gas into a plasma generation region of a substrate processing chamber, and applying energy to the fluorine-containing gas to generate a plasma in the plasma generation region. The plasma comprises fluorine radicals and fluorine ions. The method also includes filtering the plasma to provide a reactive gas having a higher concentration of fluorine radicals than fluorine ions, and flowing the reactive gas into a gas reaction region of the substrate processing chamber. The method also includes exposing the substrate to the reactive gas in the gas reaction region of the substrate processing chamber. The reactive gas etches the metal-containing layer at a higher etch rate than the reactive gas etches the silicon oxide layer.