System and methods for nanoimprint lithography
An imprint lithography system that pressurizes and depressurizes an air cavity behind a retained imprint template or substrate so as to deflect the template or substrate to aid in filling the template pattern with fluid resist and/or separating the template from the cured resist on the substrate. The system includes a controller, pressure sensors, and an impedance valve for modulating the air cavity pressure so as to reduce pressure wave oscillations within the cavity that otherwise negatively impact overlay accuracy control, fluid spread control and separation control.
1. An imprint lithography system comprising:
a chuck configured to retain an imprint lithography template or substrate such that an air cavity is defined between the retained template or substrate and the chuck;
a pressurized gas supply source and an associated pressure valve in fluid communication with the air cavity for supplying pressurized gas to the air cavity;
a vacuum supply source and an associated vacuum valve in fluid communication with the air cavity for applying vacuum to the air cavity;
an impedance valve located between the air cavity and the pressurized gas supply and vacuum supply sources and in fluid communication with each of the air cavity, the pressurized gas supply source, and the vacuum supply source that modulates an amount of gas pressure or vacuum supplied or applied to the air cavity from the pressurized gas supply source or vacuum supply source, respectively;
an air cavity sensor for sensing the amount of pressure or vacuum in the air cavity and providing an air cavity sensor input corresponding thereto;
a valve sensor for sensing an amount of pressure or vacuum at the pressure valve or vacuum valve location and providing a valve sensor input corresponding thereto; and
a controller that controls the pressure valve and the vacuum valve and that receives the air cavity and valve sensor inputs and based thereon provides an output to the impedance valve, wherein providing the output the impedance valve increases or decreases the amount of gas pressure supplied or vacuum applied to the air cavity such that the gas pressure or vacuum pressure in the cavity is modulated to reduce pressure wave oscillations within the air cavity, and
wherein the controller is further configured to alter the air cavity pressure from a first steady state to a second steady state and maintain the first steady state or second steady state or both by simultaneously supplying and dynamically balancing both pressure and vacuum to the air cavity through the impedance valve.
2. The imprint lithography system of claim 1 wherein the air cavity sensor or the valve sensor or both are dead end sensors.
3. The imprint lithography system of claim 1 wherein the chuck is configured to retain an imprint lithography template.
4. The imprint lithography system of claim 1 wherein the chuck is configured to retain an imprint lithography substrate.
5. The imprint lithography system of claim 1 wherein a relative pressure difference between the first and second steady states is 25 kPa or more.
6. The imprint lithography system of claim 5 wherein the controller is further configured to alter the air cavity pressure from the first steady state to the second steady state in less than 0.1 seconds.
7. The imprint lithography system of claim 1 wherein the first steady state or second steady state or both are controlled to within at least 0.04 kPa control accuracy.
8. A method of manufacturing a device comprising:
forming a patterned layer on a substrate using a system according to claim 1 ;
transferring a pattern of the patterned layer into the substrate; and
processing the substrate to manufacture the device.