Exposure device including an electrically aligned electronic mask for micropatterning

Abstract

Abstract An apparatus 10 for micropatterning a photoresist coated surface 12 of a semiconductor wafer 14 includes a computer 50 for controlling an image on a screen 29 of a cathode ray tube (CRT) 30. The CRT screen 29 is optically connected to a liquid crystal light valve (LCLV) 26 by a fiber optic faceplate 28. This connection is such that the computer controlled image on the CRT screen 29 is reproduced on the face 27 of the LCLV 26 as a reflective pattern of this image. An argon-ion laser 16 provides a polarized monochromatic light beam 18 that is reflected from the face 27 of the LCLV 26. This reflected beam 32 is convergently focused by a lens system 36 onto a projected area 37 of the photoresist coated wafer surface 12, thereby exposing the photoresist with an image of the LCLV reflective pattern. A helium-neon laser 38 provides a polarized monochromatic light beam 44 that is convergently focused onto the same projected area 37 of the wafer surface 12. However, the wavelength of the helium-neon provided light beam 44 is such that there is no exposure to the photoresist coated wafer surface 12. The helium-neon light beam is reflected from the projected area 37 of the wafer surface 12 and directed toward an image plane 49 of a charge coupled device (CCD) camera 48. The CCD camera 48 captures an image of the projected area 37 of the wafer surface 12 and a computer 50 digitizes this image. The computer 50 determines the position of the wafer 14 with respect to the projected reflective pattern image, and updates the image on the CRT screen 29 if the projected reflective pattern image is not properly aligned onto the wafer surface 12. Thus, the entire surface 12 of the wafer 14 may be micropatterned by moving the wafer 14 and updating the CRT screen 29 image in accordance with this movement.

Inventors

• 👤 Peter B. Mumola

Bibliographic Details