Photoresists and methods of forming and using the same are disclosed. In an embodiment, a method includes spin-on coating a first hard mask layer over a target layer; depositing a photoresist layer over the first hard mask layer using chemical vapor deposition or atomic layer deposition, the photoresist layer being deposited using one or more organometallic precursors; heating the photoresist layer to cause cross-linking between the one or more organometallic precursors; exposing the photoresist layer to patterned energy; heating the photoresist layer to cause de-crosslinking in the photoresist layer forming a de-crosslinked portion of the photoresist layer; and removing the de-crosslinked portion of the photoresist layer.