Methods for using a silylation technique to reduce cell pitch in semiconductor devices

A method comprising:

• providing a substrate having a first layer formed thereon;
• forming a second layer on the first layer, the second layer comprising photoresist;
• performing a treatment on the second layer to form at least part of the second layer into separate structures having first distances between corresponding points of the separate structures defining a first pitch, reducing a cross-linked polymer state of the separate structures using ultraviolet radiation, and performing silylation to form a protection layer over the separate structures;
• removing a first portion of the protection layer to expose the separate structures;
• removing the separate structures to form at least part of the protection layer into separate protection structures having second distances between corresponding points of the separate protection structures defining a second pitch less than the first pitch;
• and
• using the separate protection structures as an etch mask, removing an exposed portion of the first layer.

A method for forming a semiconductor device having a reduced pitch, the method comprising:

• forming a material layer on a substrate;
• forming on the material layer a patterned photoresist layer of separate photoresist structures having first distances between corresponding points of the separate photoresist structures defining a first pitch;
• exposing the patterned photoresist layer to ultraviolet radiation to alter at least one property of the patterned photoresist layer so that a cross-link degree of a portion of the patterned photoresist layer is reduced;
• silylanizing the patterned photoresist layer in a gas phase or in a liquid phase by diffusing silylamine into the patterned photoresist layer and forming a silylated layer over the surface;
• removing a first portion of the silylated layer to expose the patterned photoresist layer using an etching back process or a chemical mechanical planarization process;
• removing the patterned photoresist layer using a plasma gas to form at least part of the silylated layer into separate silylated structures having second distances between corresponding points of the separate silylated structures defining a second pitch, the second pitch being less than the first pitch;
• using the separate silylated structures as an etch mask, removing an exposed portion of the material layer;
• and
• removing the separate silylated structures thereby forming a plurality of separate material structures having the second pitch which is smaller than a photolithography process will allow.