An etching method including an etching step of bringing an etching gas which contains nitrosyl fluoride and has been converted into plasma into contact with a member to be etched (9) having an etching object and a non-etching object, and selectively etching the etching object as compared with the non-etching object. The etching step is performed in a chamber (7) containing the member to be etched (9) using a remote plasma generation device (16) provided outside the chamber (7) as a plasma generation source. The concentration of nitrosyl fluoride in the etching gas is 0.3 vol % or more, the temperature condition of the etching step is 0° C. to 250° C., and the pressure condition of the etching step is 100 Pa or more and 3 kPa or less. The etching object includes silicon nitride. Also disclosed is a method for producing a semiconductor device using the etching method.

A method of selectively etching a silicon nitride film includes a first step of disposing a target substrate having the silicon nitride film formed thereon in a processing space, a second step of introducing a gas containing H and F into the processing space, and a third step of selectively introducing radicals of an inert gas into the processing space.

A plasma etching apparatus includes a second electrode configured to support a target substrate thereon, a second RF power supply unit configured to apply a second RF power for providing a bias for ion attraction to the second electrode, and a control system including and an RF controller. The RF controller is configured to switch the second RF power supply unit between a continuous mode that executes continuous supply of the second RF power at a constant power level and a power modulation mode that executes modulation of the second RF power between a first power and a second power larger than the first power. The RF controller is preset to control the second RF power supply unit such that the second RF power supply unit is first operated in the continuous mode for plasma ignition and then is switched into the power modulation mode.

A method for selectively etching a dielectric layer with respect to an epitaxial layer or metal-based hardmask is provided. The method comprises performing a plurality of cycles. Each cycle comprises a deposition phase and an activation phase. The deposition phase comprises flowing a deposition gas, wherein the deposition gas comprises helium and a hydrofluorocarbon or fluorocarbon, forming the deposition gas into a plasma to effect a fluorinated polymer deposition, and stopping the flow of the deposition gas. The activation phase comprises flowing an activation gas comprising an ion bombardment gas, forming the activation gas into a plasma, providing an activation bias to cause ion bombardment of the fluorinated polymer deposition, wherein the ion bombardment activates fluorine from the fluorinated polymer deposition to etch the dielectric layer, and stopping the flow of the activation gas.

A method of etching a substrate including an etching film and a mask formed on the etching film is provided. The mask includes a first pattern of a first recess having a first opening and a second pattern of a second recess having a second opening. The method includes etching the etching film to a predetermined depth; depositing a protective film on the mask after the etching; and etching the etching film after the depositing. The first opening is smaller than the second opening. As a result of the depositing, the first opening of the first pattern is clogged and the second opening of the second pattern is not clogged.

Exemplary etching methods may include flowing a halogen-containing precursor into a substrate processing region of a semiconductor processing chamber. The halogen-containing precursor may be characterized by a gas density greater than or about 5 g/L. The methods may include contacting a substrate housed in the substrate processing region with the halogen-containing precursor. The substrate may define an exposed region of a hafnium-containing material. The methods may also include removing the hafnium-containing material.

There is provided a plasma etching method capable of selectively etching an etching object containing oxide of at least one of tin and indium compared to a non-etching object. The plasma etching method includes: an etching step of bringing an etching gas containing an unsaturated compound having a fluorine atom and a bromine atom in the molecule thereof into contact with a member to be etched including an etching object to be etched by the etching gas and a non-etching object not to be etched by the etching gas in the presence of plasma, performing etching while applying a bias power exceeding 0 W to a lower electrode supporting the member to be etched, and selectively etching the etching object compared to the non-etching object. The etching object contains oxide of at least one of tin and indium and the non-etching object contains at least one of a silicon-containing compound and a photoresist.

A method for selectively etching a dielectric layer with respect to an epitaxial layer or metal-based hardmask is provided. The method comprises performing a plurality of cycles. Each cycle comprises a deposition phase and an activation phase. The deposition phase comprises flowing a deposition gas, wherein the deposition gas comprises helium and a hydrofluorocarbon or fluorocarbon, forming the deposition gas into a plasma to effect a fluorinated polymer deposition, and stopping the flow of the deposition gas. The activation phase comprises flowing an activation gas comprising an ion bombardment gas, forming the activation gas into a plasma, providing an activation bias to cause ion bombardment of the fluorinated polymer deposition, wherein the ion bombardment activates fluorine from the fluorinated polymer deposition to etch the dielectric layer, and stopping the flow of the activation gas.

A method of processing a substrate that includes: flowing nitrogen-containing (N-containing) gas, dioxygen (O.sub.2), a noble gas, and a fluorocarbon into the plasma processing chamber, the plasma processing chamber configured to hold a substrate including a dielectric layer as etch target and a patterned hardmask over the target layer; while flowing the gases, generating a fluorine-rich and nitrogen-deficient plasma in the plasma processing chamber, fluorine-rich and nitrogen-deficient plasma being made of more number of fluorine species than nitrogen species; and forming a high aspect ratio feature by exposing the substrate to the fluorine-rich and nitrogen-deficient plasma to etch a recess in the dielectric layer.

A method of processing a substrate that includes: flowing an etch gas, O.sub.2, and an adsorbate precursor into a plasma processing chamber that is configured to hold the substrate including a silicon-containing dielectric layer and a patterned mask layer, the etch gas including hydrogen and fluorine; generating a plasma in the plasma processing chamber while flowing the etch gas, O.sub.2, and the adsorbate precursor, the adsorbate precursor being oxidized to form an adsorbate; and patterning, with the plasma, the silicon-containing dielectric layer on the substrate, where the adsorbate forms a sidewall passivation layer.