Abstract: Provided are methods for processing semiconductor substrates or, more specifically, etching silicon containing antireflective coatings (SiARCs) from the substrates while preserving silicon oxides layers disposed on the same substrates. An etching solution including sulfuric acid and hydrofluoric acid may be used for these purposes. In some embodiments, the weight ratio of sulfuric acid to hydrofluoric acid in the etching solution is between about 15:1 and 100:1 (e.g., about 60:1). The temperature of the etching solution may be between about 30° C. and 50° C. (e.g., about 40° C., during etching). It has been found that such processing conditions provide a SiARC etching rate of at least about 50 nanometers per minute and selectivity of SiARC over silicon oxide of greater than about 10:1 or even greater than about 50:1. The same etching solution may be also used to remove photoresist, organic dielectric, and titanium nitride.

Abstract: Two-step process sequences uniformly etch both tungsten-based and titanium-based structures on a substrate. A sequence of wet etches using peroxide and heated nitric acid uniformly recesses a metal stack that includes W, TiN, and TiAl. W, TiN and TiC are uniformly recessed by a peroxide etch at ˜25 C followed by an acid solution with a very small amount of added peroxide at ˜60 C. TiC is etched without etching trench oxides or other metals in a work-function metal stack by either (1) highly-dilute of ultra-dilute HF at 25-35 C, (2) dilute HCl at 25-60 C, (3) dilute NH4OH at 25-60 C, or (4) solution (2) or (3) with small amounts of peroxide. Other metals in the stack may then be plasma-etched without being blocked by TiC residues.

Abstract: Provided are methods for processing semiconductor substrates or, more specifically, etching silicon containing antireflective coatings (SiARCs) from the substrates while preserving silicon oxides layers disposed on the same substrates. An etching solution including sulfuric acid and hydrofluoric acid may be used for these purposes. In some embodiments, the weight ratio of sulfuric acid to hydrofluoric acid in the etching solution is between about 15:1 and 100:1 (e.g., about 60:1). The temperature of the etching solution may be between about 30° C. and 50° C. (e.g., about 40° C., during etching). It has been found that such processing conditions provide a SiARC etching rate of at least about 50 nanometers per minute and selectivity of SiARC over silicon oxide of greater than about 10:1 or even greater than about 50:1. The same etching solution may be also used to remove photoresist, organic dielectric, and titanium nitride.

Abstract: Two-step process sequences uniformly etch both tungsten-based and titanium-based structures on a substrate. A sequence of wet etches using peroxide and heated nitric acid uniformly recesses a metal stack that includes W, TiN, and TiAl. W, TiN and TiC are uniformly recessed by a peroxide etch at ˜25 C followed by an acid solution with a very small amount of added peroxide at ˜60 C. TiC is etched without etching trench oxides or other metals in a work-function metal stack by either (1) highly-dilute of ultra-dilute HF at 25-35 C, (2) dilute HCl at 25-60 C, (3) dilute NH4OH at 25-60 C, or (4) solution (2) or (3) with small amounts of peroxide. Other metals in the stack may then be plasma-etched without being blocked by TiC residues.

Abstract: Provided are methods for processing semiconductor substrates having titanium nitride (TiN) structures as well as aluminum (Al) structures and, in some embodiments, other structures, such as silicon germanium (SiGe), tantalum nitride (TaN), hafnium oxide (HfOx), silicon nitride (SiN), and/or silicon oxide (SiO2) structures. Etching solutions and processing conditions described herein provide high etching selectivity of titanium nitride relative to these other materials. As such, the titanium nitride structures can be removed (partially or completely) without significant damage to these other structures. In some embodiments, the etching rate of titanium nitride is at least about 200 Angstroms per minute and even at least about 350 Angstroms per minute, while the etching rate of aluminum and/or other materials is less than 15 Angstroms per minute. An etching solution may be kept at 40° C. to 65° C. and may include ammonium hydroxide and hydrogen peroxide (between 1:600 and 1:3,000 by weight).

Abstract: Provided are methods for processing semiconductor substrates having titanium nitride (TiN) structures as well as aluminum (Al) structures and, in some embodiments, other structures, such as silicon germanium (SiGe), tantalum nitride (TaN), hafnium oxide (HfOx), silicon nitride (SiN), and/or silicon oxide (SiO2) structures. Etching solutions and processing conditions described herein provide high etching selectivity of titanium nitride relative to these other materials. As such, the titanium nitride structures can be removed (partially or completely) without significant damage to these other structures. In some embodiments, the etching rate of titanium nitride is at least about 200 Angstroms per minute and even at least about 350 Angstroms per minute, while the etching rate of aluminum and/or other materials is less than 15 Angstroms per minute. An etching solution may be kept at 40° C. to 65° C. and may include ammonium hydroxide and hydrogen peroxide (between 1:600 and 1:3,000 by weight).

Abstract: Polycrystalline silicon (poly-Si) can be thoroughly removed without significant effect on adjacent oxides by an aqueous solution of ammonium hydroxide with smaller concentrations of hydrogen peroxide than are normally used in ammonia-peroxide mixture (APM) formulations used for cleaning. The etching selectivity of poly-Si relative to oxides can be widely tuned by varying the hydrogen-peroxide concentration. Compared to other formulations used to remove poly-Si dummy gates in logic-node fabrication, such as TMAH, these aqueous solutions are less hazardous to workers and the environment.

Abstract: Provided are methods for processing semiconductor substrates having hafnium oxide structures as well as silicon nitride and/or silicon oxide structures. Etching solutions and processing conditions described herein provide high etching selectivity of hafnium oxide relative to these other materials. As such, the hafnium oxide structures can be removed (partially or completely) without significant damage to these other structures. In some embodiments, the etching selectivity of hafnium oxide relative to silicon oxide is at least about 10 and even at least about 30. Etching rates of hafnium oxide may be between 3 and 100 Angstroms per minute. A highly diluted water based solution of hydrofluoric acid, e.g., having a dilution ratio of 1000:1 to 10,000:1, may be used for etching to achieve these etching rates and selectivity levels. The solution may be maintained at a temperature of 25° C. to 90° C. during etching.

Abstract: Provided are methods for processing semiconductor substrates or, more specifically, methods for etching silicon nitride structures without damaging photoresist structures that are exposed to the same etching solutions. In some embodiments, a highly diluted hydrofluoric acid is used for etching silicon nitride. A volumetric ratio of water to hydrofluoric acid may be between 1000:1 and 10,000:1. This level of dilution results in a low etching selectivity of photoresist to silicon nitride. In some embodiments, this selectivity is less than 0.2 and even less than 0.02. The solution may be kept at a temperature of between 60° C. and 90° C. to increase silicon nitride etching rates and to maintain high selectivity. The process may proceed until complete removal of the silicon nitride structure, while the photoresist structure may remain substantially intact.

Abstract: Provided are methods for processing semiconductor substrates. The methods involve etching silicon nitride structures using phosphoric acid solutions maintained at low temperatures, such as between about 110° C. and 130° C. These temperatures provide adequate etching rates and do not damage surrounding metal silicide and silicon oxide structures. The etching rates of silicon nitride may be 10 Angstroms per minute and greater. Lower temperatures also allow decreasing concentrations of phosphoric acid in the etching solutions, which in some embodiments may be less than 90 weight percent. As a result, more selective etching of the silicon nitride structures may be achieved. This selectivity may be as high as hundred times relative to the silicide and silicon oxide structures. The surface conductivity of the silicide structures may remain substantially unchanged by this etching process.

Abstract: A method for fabricating an integrated circuit from a semiconductor substrate having formed thereon over a first portion of the semiconductor substrate a hard mask layer and having formed thereon over a second portion of the semiconductor substrate an oxide layer. The first portion and the second portion are electrically isolated by a shallow trench isolation feature. The method includes removing the oxide layer from over the second portion and recessing the surface region of the second portion by applying an ammonia-hydrogen peroxide-water (APM) solution to form a recessed surface region. The APM solution is provided in a concentration of ammonium to hydrogen peroxide ranging from about 1:1 to about 1:0.001 and in a concentration of ammonium to water ranging from about 1:1 to about 1:20. The method further includes epitaxially growing a silicon-germanium (SiGe) layer on the recessed surface region.

Abstract: Provided are methods for processing semiconductor substrates. The methods involve etching silicon nitride structures using phosphoric acid solutions maintained at low temperatures, such as between about 110° C. and 130° C. These temperatures provide adequate etching rates and do not damage surrounding metal silicide and silicon oxide structures. The etching rates of silicon nitride may be 10 Angstroms per minute and greater. Lower temperatures also allow decreasing concentrations of phosphoric acid in the etching solutions, which in some embodiments may be less than 90 weight percent. As a result, more selective etching of the silicon nitride structures may be achieved. This selectivity may be as high as hundred times relative to the silicide and silicon oxide structures. The surface conductivity of the silicide structures may remain substantially unchanged by this etching process.

Abstract: A method for fabricating an integrated circuit from a semiconductor substrate having formed thereon over a first portion of the semiconductor substrate a hard mask layer and having formed thereon over a second portion of the semiconductor substrate an oxide layer. The first portion and the second portion are electrically isolated by a shallow trench isolation feature. The method includes removing the oxide layer from over the second portion and recessing the surface region of the second portion by applying an ammonia-hydrogen peroxide-water (APM) solution to form a recessed surface region. The APM solution is provided in a concentration of ammonium to hydrogen peroxide ranging from about 1:1 to about 1:0.001 and in a concentration of ammonium to water ranging from about 1:1 to about 1:20. The method further includes epitaxially growing a silicon-germanium (SiGe) layer on the recessed surface region.

Abstract: A system and method of depositing coatings on a substrate includes providing a substrate in contact with air, and providing a plasma source (12) having a housing (16) surrounding a first electrode (18) and a second electrode (20) spaced from the first electrode. A plasma is generated by applying a signal to the first electrode and exciting a gas between the first electrode and the second electrode. A substantially uniform flux of at least one reactive specie is generated over an area larger than 1 cm2. The plasma is emitted into the air and toward the substrate. Various embodiments of the system and method allow high speed deposition of coatings on even thermally-sensitive substrates without the need of a chamber enclosing the substrate.