Abstract: A method is provided for an etching process. The method includes dispensing a liquid electrolyte layer over a layer-to-be-etched on a substrate. A first electrode is coupled to the substrate, and a second electrode is coupled to the liquid electrolyte layer. An alternating voltage is applied at different frequencies between these electrodes. Impedance data is collected in response to the alternating voltage. The etching process is then performed with an etching parameter selected based on the collected impedance data, allowing for precise control and improved uniformity of the layer-to-be-etched.

Abstract: Embodiments of improved methods are provided to form ordered structures on a surface of a substrate using direct self-assembly (DSA) of ionic liquid crystals (ILCs). More specifically, various embodiments of methods are provided to control the phase of an ordered structure formed on a substrate surface via self-assembly of ILCs having cation head groups, alkyl tail groups having a plurality of hydrocarbons and anions. In the embodiments disclosed herein, the phase of the ordered structure is controlled by replacing the hydrogen (H) atoms of the hydrocarbons included the alkyl chain with larger sized functional groups. Adding larger sized functional groups to the alkyl chain changes the phase of the ordered structure by: (a) increasing the separation between the hydrophilic (cation) and hydrophobic (alkyl tail) groups of the ILCs, and (b) changing the orientation of alkyl tails within the tail groups of the self-assembled ILCs.

Abstract: Various embodiments of methods are provided for etching tungsten in a wet ALE process. The methods disclosed herein use a wide variety of techniques and wet etch chemistries to: (a) oxidize a tungsten surface and form a self-limiting, tungsten oxide passivation layer in a surface modification step of the wet ALE process, and (b) selectively remove the tungsten oxide passivation layer in a dissolution step of the wet ALE process. In the embodiments disclosed herein, ligand-assisted dissolution is used to selectively remove the tungsten oxide passivation layer without removing the unmodified tungsten surface underlying the tungsten oxide passivation layer. The ligand added to the dissolution solution prevents the dissolution solution from attacking and removing the unmodified tungsten surface.

Abstract: The present disclosure provides various embodiments of methods for protecting an exposed metal surface of a metal layer prior to etching the metal layer using wet etch chemistry optimized for the bulk metal layer. In the embodiments disclosed herein, the exposed metal surface of the metal layer is protected by depositing a sacrificial metal layer on the exposed metal surface prior to etching the metal layer with the wet etch chemistry. The sacrificial metal layer protects the exposed metal surface by preventing oxidative passivation of the metal surface before and during etching the metal layer with the wet etch chemistry. In some embodiments, the techniques disclosed herein may be used to protect a surface of a ruthenium (Ru) layer prior to etching the ruthenium layer using halogenating etch chemistries in a wet atomic layer etching (ALE) process.

Abstract: Various embodiments of methods are provided herein for oxidizing a surface of a semiconductor substrate. In the disclosed embodiments, gas-phase oxidizing free radicals are generated and used to oxidize an exposed surface of a material and form a thin oxide film there on. The gas-phase oxidizing free radicals are generated via ultraviolet (UV) photolysis of vaporized peroxide solutions. In some embodiments, an aqueous hydrogen peroxide (H2O2) solution is vaporized and photolyzed with UV light to form gas-phase hydroxyl (HO*) free radicals, which oxidize the exposed surface of the material to form a thin oxide film on the exposed surface of the material.

Abstract: The present disclosure provides a new wet atomic layer etch (ALE) process for etching silicon dioxide (SiO2) materials. More specifically, the present disclosure provides various embodiments of methods that utilize new etch chemistries for etching a SiO2 layer in a cyclic wet ALE process. The new etch chemistries disclosed herein use an anhydrous basic surface modification solution to create self-limiting reactions on exposed surfaces of the SiO2 layer and form a silicate passivation layer, which is insoluble in the surface modification solution, but readily soluble in a dissolution solution.

Abstract: New methods are provided for conditioning a surface of a material to be etched prior to etching the material. More specifically, the present disclosure provides various embodiments of methods for conditioning a surface of a metal layer prior to etching the metal layer using etch chemistry optimized for the bulk metal layer. In some embodiments, the techniques disclosed herein may be used to condition a surface of a ruthenium (Ru) layer prior to etching the ruthenium layer using halogenating etch chemistries in a wet atomic layer etching (ALE) process.

Abstract: Embodiments of improved process flows and methods are provided to pattern a semiconductor substrate using direct self-assembly (DSA) of metalate salt ionic liquid crystals (ILCs) having metalate anions. After self-assembly of the metalate salt ILCs into ordered structures, an oxidation process is used to remove the organic components of the ordered structures and convert the metalate anions into metal oxide patterns. In addition to providing a robust metal oxide pattern, which can be transferred to the underlying substrate, the process flows and methods disclosed herein enable ILCs to be used as pitch multipliers in advanced patterning techniques.

Abstract: Various embodiments of methods are provided for etching titanium nitride (TiN) and other transition metal nitride materials in a wet ALE process. The methods disclosed herein use a wide variety of wet etch chemistries to: (a) halogenate a TiN surface and form a self-limiting, titanium halide or titanium oxyhalide passivation layer in a surface modification step of the wet ALE process, and (b) selectively remove the titanium halide or titanium oxyhalide passivation layer in a dissolution step of the wet ALE process. In the embodiments disclosed herein, a surface modification solution containing a halogenation agent dissolved in non-aqueous solvent is used to form a self-limiting, titanium halide or titanium oxyhalide passivation layer, which is selectively removed in an acidic dissolution solution via reactive dissolution.

Abstract: Embodiments of processes and methods that provide selective etching of silicon nitride are disclosed herein. More specifically, new processes, methods and etch chemistries are provided to selectively etch silicon nitride layers formed on a substrate, while protecting silicon oxide layers formed on the same substrate. In the method embodiments, a substrate having a silicon nitride (SiN) layer and a silicon oxide layer formed on the same substrate is exposed to an alkylating agent, which reacts with the amine groups on the exposed SiN surfaces to form an alkylated surface layer on the SiN layer. The substrate is exposed to a fluorinating agent to remove the alkylated surface layer and selectively etch the SiN layer without significantly etching the silicon oxide layer. The disclosed methods can be used to selectively etch silicon nitride over silicon oxide using a wet or dry process.

Abstract: Various embodiments of methods are provided that utilize an overlayer to accelerate etching of an underlayer provided on a semiconductor substrate. In the embodiments disclosed herein, an ultrathin (e.g., less than 2 nm) overlayer film is deposited onto an underlayer to enhance the local etch rate of (and selectivity to) the underlayer during a dry chemical etch process performed at low temperature (e.g., less than or equal to 100° C.). The overlayer film, which comprises a metal oxide or metal fluoride material, accelerates etching of the underlayer at temperatures below the threshold energy typically needed to enable chemical reactions on a bare underlayer surface by providing a medium for more effective chemical reactions at the surface of the underlayer.

Abstract: The present disclosure provides a new wet atomic layer etch (ALE) process for etching high-k dielectric materials. More specifically, the present disclosure provides various embodiments of methods that utilize new etch chemistries for etching transition metal oxide dielectric materials in a cyclic wet ALE process. In the example embodiments provided herein, new etch chemistries and methods are provided for etching zirconium dioxide (ZrO2), hafnium dioxide (HfO2) and HfxZr(1-x)O2 dielectrics in a cyclic wet ALE process. However, the wet ALE techniques described herein are not strictly limited to the example materials discussed herein and can be applied to other transition metals and transition metal oxides.

Abstract: The present disclosure provides a non-isothermal wet atomic layer etch (ALE) process for etching polycrystalline materials, such as metals, metal oxides and silicon-based materials, formed on a substrate. More specifically, the present disclosure provides various embodiments of methods that utilize thermal cycling in a wet ALE process to independently optimize the reaction temperatures utilized within individual processing steps of the wet ALE process. Like conventional wet ALE processes, the wet ALE process described herein is a cyclic process that includes multiple cycles of surface modification and dissolution steps. Unlike conventional wet ALE processes, however, the wet ALE process described herein is a non-isothermal process that performs the surface modification and dissolution steps at different temperatures. This allows independent optimization of the surface modification and dissolution reactions.

Abstract: Embodiments of improved methods are provided to form ordered structures on a surface of a substrate using direct self-assembly (DSA) of ionic liquid crystals (ILCs). More specifically, various embodiments of methods are provided to control the phase of an ordered structure formed on a substrate surface via self-assembly of ILCs having cation head groups, alkyl tail groups having a plurality of hydrocarbons and anions. In the embodiments disclosed herein, the phase of the ordered structure is controlled by replacing the hydrogen (H) atoms of the hydrocarbons included the alkyl chain with larger sized functional groups. Adding larger sized functional groups to the alkyl chain changes the phase of the ordered structure by: (a) increasing the separation between the hydrophilic (cation) and hydrophobic (alkyl tail) groups of the ILCs, and (b) changing the orientation of alkyl tails within the tail groups of the self-assembled ILCs.

Abstract: Various embodiments of methods are provided for etching tungsten in a wet ALE process. The methods disclosed herein use a wide variety of techniques and wet etch chemistries to: (a) oxidize a tungsten surface and form a self-limiting, tungsten oxide passivation layer in a surface modification step of the wet ALE process, and (b) selectively remove the tungsten oxide passivation layer in a dissolution step of the wet ALE process. In the embodiments disclosed herein, ligand-assisted dissolution is used to selectively remove the tungsten oxide passivation layer without removing the unmodified tungsten surface underlying the tungsten oxide passivation layer. The ligand added to the dissolution solution prevents the dissolution solution from attacking and removing the unmodified tungsten surface.

Abstract: Various embodiments of methods are provided for etching tungsten in a wet ALE process. The methods disclosed herein use a wide variety of wet etch chemistries to: (a) halogenate a tungsten surface and form a self-limiting, tungsten halide passivation layer in a surface modification step of the wet ALE process, and (b) selectively remove the tungsten halide passivation layer in a dissolution step of the wet ALE process. In the embodiments disclosed herein, a surface modification solution containing a halogenation agent dissolved in non-aqueous solvent is used to form a self-limiting, tungsten halide passivation layer, which is selectively removed in an aqueous dissolution solution via reactive dissolution/hydrolysis.

Abstract: The present disclosure provides a new wet atomic layer etch (ALE) process for etching silicon dioxide (SiO2) materials. More specifically, the present disclosure provides various embodiments of methods that utilize new etch chemistries for etching a SiO2 layer in a cyclic wet ALE process. The new etch chemistries disclosed herein use an anhydrous basic surface modification solution to create self-limiting reactions on exposed surfaces of the SiO2 layer and form a silicate passivation layer, which is insoluble in the surface modification solution, but readily soluble in a dissolution solution.

Abstract: The present disclosure provides wet processing systems and methods for improving etch uniformity across a semiconductor substrate when etching a silicon surface with a hydrofluoric acid (HF) and nitric acid (HNO3) etch solution (otherwise referred to herein as an HF+HNO3 etch solution). More specifically, the present disclosure provides single wafer wet processing systems and methods that improve etch uniformity across a silicon surface of a semiconductor substrate by increasing the concentration of nitrous acid (HNO2) in the HF+HNO3 etch solution used to etch the silicon surface prior to dispensing the HF+HNO3 etch solution onto the silicon surface.

Abstract: Embodiments of improved methods are provided to form ordered structures on a surface of a substrate using direct self-assembly (DSA) of ionic liquid crystals (ILCs). More specifically, various embodiments of methods are provided to control the pitch of a layered structure formed on a substrate surface via self-assembly of ILCs having cation head groups, alkyl tail groups and anions. In the embodiments disclosed herein, the pitch of the layered structure is controlled by: (a) controlling the cation/anion charge ratio of the cation head groups and anions included within the ILCs, and/or (b) adding an ionic liquid to a solution comprising the ILCs.

Abstract: Aspects of the present disclosure provide a semiconductor structure. For example, the semiconductor structure can include a wafer and luminescent thermometers formed on a surface of the wafer. The luminescent thermometers can be configured to receive incident light and emit light. The emitted light can have an intensity that depends on a temperature of a portion of the surface of the wafer where the luminescent thermometers are formed.