Development method for patterning metal oxide photoresist

A method for processing a substrate, the method comprising:

• receiving the substrate on a substrate holder disposed in a processing chamber, the substrate comprising a metal oxide photoresist (MOR) layer disposed over an underlying layer, the MOR layer comprising a first region and a second region;
• performing a low-temperature gas development process for a first processing time in the processing chamber to form a modified region from the first region, the low-temperature gas development process comprising exposing the substrate to a processing gas at a first temperature, the processing gas interacting with the first region to form the modified region;
• and
• after performing the low-temperature gas development process for the first processing time, exposing the substrate to a plasma for a second processing time at a second temperature in the processing chamber to remove the modified region and remaining portions of the first region and to form a patterned MOR mask, the plasma being formed from an etch gas and an additive gas.

A system for processing a substrate, the system comprising:

• a processing chamber, the processing chamber comprising a substrate holder, a top plate, a bottom plate, and a dielectric sidewall;
• a gas system coupled to the processing chamber through a gas inlet and a gas outlet, the gas system comprising a processing gas, an etch gas, and an additive gas;
• a temperature control system coupled to the substrate holder;
• an RF source power supply electrically coupled to a helical electrode;
• an RF bias power supply electrically coupled to the substrate holder;
• and
• a controller coupled to the processing chamber, and a memory storing instructions to be executed in the controller, the instructions when executed cause the controller to:
• receive the substrate on the substrate holder disposed in the processing chamber, the substrate comprising a metal oxide photoresist (MOR) layer disposed over an underlying layer, the MOR layer comprising an exposed MOR region having been exposed to an actinic radiation and an unexposed MOR region,
• perform a gas development process for a first processing time in the processing chamber, the gas development process comprising exposing the substrate to the processing gas at a first temperature to form a modified unexposed MOR region from the unexposed MOR region, the modified unexposed MOR region comprising an element of the processing gas, and
• after performing the gas development process for the first processing time, expose the substrate to a plasma for a second processing time at a second temperature in the processing chamber to remove the modified unexposed MOR region to form a patterned MOR mask, the plasma being formed from the etch gas and the additive gas.