US Patent 9772555 Methods of forming patterns using photoresists

In a method of forming a pattern, a lower coating layer and a photoresist layer are sequentially formed on an object layer. An exposure process may be performed such that the photoresist layer is divided into an exposed portion and a non-exposed portion. A portion of the lower coating layer overlapping or contacting the exposed portion is at least partially transformed into a polarity conversion portion that has a polarity substantially identical to that of the exposed portion. The non-exposed portion of the photoresist layer is selectively removed.