System and methods of mold/substrate separation for imprint lithography

A system for separating a mold and an imprinted substrate in imprint lithography comprising:

• a mold holding fixture for holding a mold having a mold surface with nanostructures;
• a substrate holding fixture for holding a substrate having a molding surface;
• a stage assembly having three axis movement;
• a contact force sensors positioned for sensing the separation force between the moldable surface and the molding surface during separation;
• an overhead camera for observation of separation boundary;
• and
• at least one vacuum pump;

A system for separating a mold and an imprinted substrate in imprint lithography comprising:

• a mold holding fixture for holding a mold having a mold surface with nanostructures;
• a substrate holding fixture for holding a substrate having a molding surface;
• a stage assembly having three axis movement;
• a contact force sensors positioned for sensing the separation force between the moldable surface and the molding surface during separation;
• a chamber housing defining a chamber having at least a mold held by the mold holding fixture and the substrate held by the substrate holding fixture positionable therein, the chamber housing configured enabling the applying of a pressure inside the chamber that is higher and/or lower than atmospheric pressure;
• a pressure regulator and a manifold each being fluidly coupled to the chamber for changing the pressure inside the chamber;
• a gas reservoir of high pressure, a regulator and piping to allow the high pressure gas;
• at least one vacuum pump;
• an overhead camera for observation of separation boundary;
• and
• means to divide the chamber into two fluidly separate sub-chambers, each sub-chamber being configured for a separate controlled sub-chamber environment including a separate pressure and/or vacuum, a separate gas content, and a separate gas flow rate into and out thereof.

A method of patterning a substrate with microstructure and nanostructure patterns in roller imprint lithography comprising the steps of:

• applying moldable material on the substrate surface;
• providing a mold having a molding surface with the patterns;
• at least one of the moldable or the molding surfaces is part of a roller, or at least one backside of the mold and the substrate is contacting a roller;
• contacting the moldable surface with the molding surface and press;
• and
• curing the contacted area and separate;

A system for patterning substrate surfaces with microstructure and nanostructure patterns in roller imprint lithography compromising:

• a mold having a mold surface with the patterns;
• a substrate having a molding surface;
• contact force sensors positioned for sensing the force at different locations of the roller system;
• at least a chamber housing configured enabling the applying of a pressure inside the chamber that is higher and/or lower than atmospheric pressure;
• or a ACP head enabling the applying of a pressure on the output of the head;
• a pressure regulator and a manifold each being fluidly coupled to the chamber for changing the pressure inside the chamber or coupled to the ACP head to change the output pressure of the head;
• a gas reservoir of high pressure, a regulator and piping to allow the high pressure gas;
• at least one vacuum pump;
• moldable material dispensing head, or moldable material bath in contact with at least a section of the substrate, or a roller in contact with the substrate and moldable material;
• a vapor treatment chamber to coat vapor of chemicals on a section of the mold or the substrate;
• rollers to move at least one of substrate and mold;
• and
• means to control the thickness of the moldable materials by contacting and taking away extra materials;

A method of patterning a roller mold with microstructure and nanostructure patterns comprising the steps of:

• having a substrate with the patterns on the surface;
• coating roller mold with surfactant coating;
• roll the mold on the substrate patterned surface with a controlled pressure, so the pattern on the substrate is transferred to the mold surface;
• removing the surfactant coating exposed in the air;
• plating the roller mold with metal;
• rotating the roller mold to polish its surface so that the patterns are exposed in the air and the metal surface is smooth;
• and
• removing the remaining surfactant and patterns transferred initially from the substrate.

A method of patterning a roller mold with microstructure and nanostructure patterns comprising the steps of:

• coating the roller surface with photoresist;
• using projection optics with UV light and photomask to exposure a line of the resist on the surface of the roller;
• rotating the roller to next field and run exposure again;
• keeping rotating and exposure each time until all required areas on the roller surface are exposed;
• placing roller into a developer to remove unwanted resists;
• and
• etching the pattern into the roller using a wet etching or a dry etching.

A method of patterning a roller mold with microstructure and nanostructure patterns comprising the steps of:

• having a substrate with the molding pattern on the surface;
• coating a roller surface with moldable material;
• and
• contacting and rotating the roller with the substrate under a controlled pressure and curing the resists while rotating.

A method of patterning a roller mold with microstructure and nanostructure patterns comprising the steps of:

• having a flexible substrate with the molding pattern on the front surface;
• coating the roller surface, the back surface of the substrate, or both with either glue or a magnetic material;
• and
• rotating the roller on the back surface of the substrate to wrap the substrate around the roller;

A system for patterning substrate surfaces with microstructure and nanostructure patterns in step and repeat imprint lithography, compromising:

• a mold having a molding surface with the patterns;
• a substrate having a molding surface not smaller than the patterning area of the mold;
• a gantry for holding mold holder;
• a multi-axis stages;
• contact force sensors positioned for sensing the forces during imprint and separation;
• a pressure regulator and a manifold each being fluidly coupled to the system;
• a gas reservoir of high pressure, a regulator and piping to allow the high pressure gas;
• at least one vacuum pump;
• a material dispensing system for placing moldable material on the substrate;
• a vibration control table;
• a robot system with cassettes for automatically loading and unloading of substrates and molds;
• a microscopic system for measuring the spatial relation between the mold and the substrates at multiple locations;
• a UV exposure light and reflective optics;
• a mold holder which has center opening and can change the mold size in the XY plane;
• and
• means to press one area of the substrate using the mold at a time, then separate and continue with other areas.

A method of patterning a substrate with microstructure and nanostructure patterns in step and repeat imprint lithography comprising the steps of:

• providing a mold having a molding surface with the patterns;
• applying moldable material on an area of the substrate surface;
• adjusting the gaps between the mold and the substrate so the moldable surface and molding surface is in parallel;
• approaching the substrate to the mold while aligning them according to the alignment marks on the mold and the substrate;
• contacting the moldable surface with the molding surface;
• applying pressure and hold a certain time;
• curing the contacted area;
• separating the moldable surface from molding surface with patterns left on the moldable surface;
• and
• moving to next area and repeating the pressing again until all areas of the moldable surface is patterned.