Quantum state control interference lithography and trim double patterning for 32-16 nm lithography

摘要

Double patterning has been proposed as a method to extend DUV lithography to 32nm and below. Here, a new form of double, or higher, multiple exposure technique is proposed. This new form of lithography uses a combination of Quantum State Control (QuSC) chemistry, Amplitude Modulation Optical Lithography (AMOL), and multiple micro-stepped exposures, without development between exposures. Further it is proposed to use this form of lithography (called QuSC-litho), to pattern a perfect grating grid, and to trim this grid with an earlier generation lithography tool. QuSC lithography uses short optical pulses to modulate a photochemical pathway while an intermediate is still in a defined vibrational excited state. This is a variation of Stimulated Emission Depletion Microscopy (STED) developed for fluorescence microscopy. With this approach immersion tools that produce 90 nm pitch and 45 nm features should be able to pattern levels with 22 nm features with a 1:1 line-space ratio. This approach is much less sensitive to misalignment than present double patterning approaches. Key to successful deployment of QuSC lithography is defining a resist photochemistry consistent with the QuSC process. There are several approaches to Photo Acid Generator (PAG) - matrix interaction that may be consistent with this approach.