Etching methods and apparatus and substrate assemblies produced therewith

A method of anisotropically etching a substrate assembly, comprising:

• forming a resist layer on a surface of the substrate assembly, the resist layer having a thickness;
• defining patterns in the resist layer by removing portions of the resist layer;
• and
• exposing the resist layer and the surface of the substrate assembly to a plasma generated in a gas mixture consisting essentially of a chlorinated hydrocarbon gas and simultaneously etching a portion of the substrate exposed by the step of removing portions of the resist layer and increasing the thickness of the resist layer with the plasma.

A method of plasma etching a surface of a substrate assembly, comprising:

• forming a layer of a resist on the surface of the substrate assembly, the resist layer having a nominal thickness tN;
• patterning the resist by removing selected portions of the resist to expose corresponding portions of the surface of the substrate assembly;
• exposing the resist layer and the exposed portions of the surface of the substrate assembly to a resist-conserving etch;
• and
• exposing the resist layer and the exposed portions of the surface of the substrate assembly to a resist-consuming etch.

A method of plasma etching a surface of a substrate assembly having patterns defined by a resist layer, comprising:

• enclosing the substrate assembly in a silicon or silicon carbide enclosure;
• selecting a surface of the substrate assembly to be etched;
• selecting a gas or gas mixture;
• adjusting a flow rate of the gas or gas mixture into the chamber so that the resist layer etches at a rate that is at least 10 times slower than the etch rate of the selected surface;
• exposing the substrate assembly to a gas flow;
• and
• generating a plasma in the gas flow with an applied magnetic field.

A method of anisotropically etching a substrate assembly, comprising:

• forming a resist layer on a surface of the substrate assembly, the resist layer having a thickness;
• defining patterns in the resist layer by removing portions of the resist layer;
• exposing the resist layer and the surface of the substrate assembly to a first plasma etch and simultaneously etching a portion of the substrate exposed by the step of removing portions of the resist layer and increasing the thickness of the resist layer with the plasma etch;
• and
• exposing the resist layer and the surface of the substrate assembly to a second plasma etch and simultaneously etching a portion of the substrate exposed by the step of removing portions of the resist layer and decreasing the thickness of the resist layer with the second plasma etch.

A method for plasma etching an oxide layer formed on a silicon wafer, the oxide layer partially covered with a patterned layer of a resist, the method comprising:

• exposing the oxide layer and the patterned layer of resist to a first gas consisting essentially of CH2F2;
• generating a plasma within the first gas;
• directing ions from the plasma onto exposed portions of the oxide layer;
• adjusting the flow of the first gas so that the exposed portions of the oxide layer are etched such that the oxide layer is etched at a rate at least five times faster than the resist;
• and
• etching the portion of the substrate assembly that is not covered by the resist with a plasma generated in a flow of a second halogenated hydrocarbon containing a second gas that etches the surface of the substrate and the resist layer.

A method of etching a substrate assembly, comprising:

• forming a resist layer on a surface of the substrate assembly;
• defining a feature on the surface of the substrate assembly by patterning the resist layer so that the resist layer is removed from at least a portion of the substrate;
• etching the portion of the substrate that is not covered by the resist layer and depositing a material on the resist layer with a first plasma generated in a flow of a first halogenated hydrocarbon containing gas so that the etched feature has an aspect ratio of at least 5:1;
• and
• etching the portion of the substrate assembly that is not covered by the resist with a second plasma generated in a flow of a second halogenated hydrocarbon containing gas that etches the surface of the substrate and the resist layer.

A method of etching a substrate assembly, comprising:

• selecting a gas or gas mixture;
• providing a predetermined flow rate of the gas or gas mixture to an enclosure at a predetermined pressure;
• maintaining the temperature of the enclosure at about 140 C;
• patterning a surface of the substrate assembly with a resist;
• situating the substrate assembly inside the enclosure;
• heating or cooling the substrate assembly to achieve a substrate assembly temperature of about −10 C;
• providing a silicon getter at a temperature of about 200 C within the enclosure;
• producing a plasma in the gas or gas mixture in the enclosure with an applied radio-frequency excitation at a frequency of between 1 and 3 MHz;
• exposing the substrate assembly to the plasma;
• and
• etching the surface of the substrate assembly at a rate that is at least 10 time greater than a rate at which the resist etches.