Etching methods and apparatus and substrate assemblies produced therewith

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 gas consisting essentially of CH2F2;
• generating a plasma within the gas;
• directing ions from the plasma onto exposed portions of the oxide layer;
• and
• adjusting the flow of the 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.

A method of etching a substrate assembly comprising:

• defining a pattern in a resist layer on a surface of the substrate assembly by exposing a portion of the surface;
• selecting a gas or gas mixture;
• exposing the substrate assembly to a plasma generated in the gas or gas mixture;
• selecting a flow rate of the gas or gas mixture so that exposed portion of the substrate assembly is etched without thinning the resist.

A method of etching a high aspect ratio feature having a controlled profile, comprising:

• selecting a substrate assembly
• selecting a surface of the substrate assembly to be etched;
• selecting a depth D and width d of the high aspect ratio feature such that D/d>10;
• depositing a resist layer of thickness less than about D/5 on the selected surface of the substrate assembly;
• etching the high aspect ratio feature into the selected surface with a controlled profile.

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;
• 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 plasma etch;
• etching the exposed portions of the substrate assembly at a rate that is at least five times faster than a rate at which the resist etches.

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 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.

A method of manufacturing comprising:

• providing a substrate assembly having a first surface with a first surface feature;
• removing material from at least one first region of the first surface;
• and
• thickening material on at least second region of the first surface simultaneously while removing material from the first region.

A method of manufacturing, comprising:

• patterning a resist layer on a substrate assembly so that portions of the substrate assembly are exposed;
• etching the exposed portions of the substrate assembly with a resist-conserving etch;
• and
• etching the exposed portions of the substrate assembly with a resist-consuming etch.

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;
• and
• exposing the resist layer and the exposed portions of the surface of the substrate assembly to a resist-conserving etch.