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: 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 silicon nitride from a substrate comprising a silicon nitride 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 silicon nitride layer at a higher etch rate than the reactive gas etches the silicon oxide layer.

Abstract: A tunable plasma etch process includes generating a plasma in a controlled flow of a source gas including NH3 and NF3 to form a stream of plasma products, controlling a flow of un-activated NH3 that is added to the stream of plasma products to form an etch gas stream; and controlling pressure of the etch gas stream by adjusting at least one of the controlled flow of the source gas and the flow of un-activated NH3 until the pressure is within a tolerance of a desired pressure. An etch rate of at least one of polysilicon and silicon dioxide by the etch gas stream is adjustable by varying a ratio of the controlled flow of the source gas to the flow of un-activated NH3.

Abstract: A method of etching exposed silicon oxide on patterned 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 combine with a nitrogen-and-hydrogen-containing precursor. Reactants thereby produced etch the patterned heterogeneous structures with high silicon oxide selectivity while the substrate is at high temperature compared to typical Siconi™ processes. The etch proceeds without producing residue on the substrate surface. The methods may be used to remove silicon oxide while removing little or no silicon, polysilicon, silicon nitride or titanium nitride.

Abstract: A method of etching patterned heterogeneous silicon-containing structures is described and includes a remote plasma etch with inverted selectivity compared to existing remote plasma etches. The methods may be used to conformally trim polysilicon while removing little or no silicon oxide. More generally, silicon-containing films containing less oxygen are removed more rapidly than silicon-containing films which contain more oxygen. Other exemplary applications include trimming silicon carbon nitride films while essentially retaining silicon oxycarbide. Applications such as these are enabled by the methods presented herein and enable new process flows. These process flows are expected to become desirable for a variety of finer linewidth structures. Methods contained herein may also be used to etch silicon-containing films faster than nitrogen-and-silicon containing films having a greater concentration of nitrogen.

Abstract: Methods of etching exposed silicon on patterned heterogeneous structures is described and includes a remote plasma etch 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 exposed regions of silicon. The plasmas effluents react with the patterned heterogeneous structures to selectively remove silicon while very slowly removing other exposed materials. The silicon selectivity results, in part, from a preponderance of hydrogen-containing precursor in the remote plasma which hydrogen terminates surfaces on the patterned heterogeneous structures. A much lower flow of the fluorine-containing precursor progressively substitutes fluorine for hydrogen on the hydrogen-terminated silicon thereby selectively removing silicon from exposed regions of silicon.

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: 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 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 etching exposed silicon-nitrogen-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-nitrogen-and-carbon-containing material. The plasma effluents react with the patterned heterogeneous structures to selectively remove silicon-nitrogen-and-carbon-containing material from the exposed silicon-nitrogen-and-carbon-containing material regions while very slowly removing selected other exposed materials. The silicon-nitrogen-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 controls the number of ionically-charged species that reach the substrate.

Abstract: A method of etching exposed patterned heterogeneous structures is described and includes a remote plasma etch formed from a reactive precursor. The plasma power is pulsed rather than left on continuously. Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents selectively remove one material faster than another. The etch selectivity results from the pulsing of the plasma power to the remote plasma region, which has been found to suppress the number of ionically-charged species that reach the substrate. The etch selectivity may also result from the presence of an ion suppression element positioned between a portion of the remote plasma and the substrate processing region.

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 anisotropically dry-etching exposed substrate material on a patterned substrate is described. The patterned substrate has a gap formed in a single material made from, for example, a silicon-containing material or a metal-containing material. The method includes directionally ion-implanting the patterned structure to implant the bottom of the gap without implanting substantially the walls of the gap. Subsequently, a remote plasma is formed using a fluorine-containing precursor to etch the patterned substrate such that either (1) the walls are selectively etched relative to the floor of the gap, or (2) the floor is selectively etched relative to the walls of the gap. Without ion implantation, the etch operation would be isotropic owing to the remote nature of the plasma excitation during the etch process.

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 tunable plasma etch process includes generating a plasma in a controlled flow of a source gas including NH3 and NF3 to form a stream of plasma products, controlling a flow of un-activated NH3 that is added to the stream of plasma products to form an etch gas stream; and controlling pressure of the etch gas stream by adjusting at least one of the controlled flow of the source gas and the flow of un-activated NH3 until the pressure is within a tolerance of a desired pressure. An etch rate of at least one of polysilicon and silicon dioxide by the etch gas stream is adjustable by varying a ratio of the controlled flow of the source gas to the flow of un-activated NH3.

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: 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.