METHOD OF MAKING A SEMICONDUCTOR DEVICE USING TREATED PHOTORESIST

摘要

Photoresist, which contains hydrogen, is patterned over a semiconductor substrate then treated with either a molecular halogen or a liquid fluorinating agent in order to improve subsequent ion implantation. Hydrogen is replaced, to whatever extent is found desirable, with the halogen. Molecular fluorine (F₂) has been found to be particularly effective as the molecular halogen. Molecular fluorine (F₂) reacts very efficiently in replacing the hydrogen and further has the benefit of continuing to penetrate into the patterned photoresist so that the entire patterned photoresist layer can have the hydrogen atoms replaced with fluorine atoms if the molecular fluorine flow is continued long enough. The resulting treated photoresist is much more resistant to penetration by implanted ions so that the photoresist can be deposited to a lesser thickness. This is beneficial in shadowing problems such as can occur in halo implants and where the patterned photoresist has a high aspect ratio.