Maskless based lithography methods

Abstract

Embodiments described herein relate to methods of forming layers using maskless based lithography. In these embodiments, the methods implement ladders of dose change such that a geometric shape can be divided into overlaying sections. The overlaying sections can include a different dose of each section such that taper control can be achieved. The taper can be achieved by manipulating the geometry 'mask data' into overlaying sections that are exposed by various doses controlled by pixel blending (PB) exposure techniques. To perform the methods described herein, a maskless lithography tool is used. The maskless lithography tool includes a controller that performs software based “mask data” manipulation. As such, because the methods are performed by software with no mask, there is much more flexibility to tune the taper angles and/or photoresist thickness residuals for multi-tone/gray tone mask features without any additional mask cost and fabrication time, providing advantages over conventional lithography methods using masks.