Resist materials tone reversal

The chemistry of the DQN materials has been modified such that they function as a high-resolution, high-contrast, negative-tone resist system that is as devoid of distortion due to swelling as the standard, positive DQN system 14, 15). This tone reversal of the DQN system is accomplished by addition of an appropriate base to the formulation. 

In addition to the polarity change, the tone of certain resist materials may be reversed simply by changing the wavelength of exposure. For example, copolymers of methacrylonitrile and methacrylic acid undergo main-chain scission when exposed to DUV radiation to provide positive-tone im-... 

---