Paper PS2-ThM4
Roughness and Selectivity Trade Off during Patterning using Next Generation Resist

Thursday, November 10, 2016, 9:00 am, Room 104B

Optical lithography has reached its physical limit and eventual capacity to extend validity of Moore’s law. Augmentation of 193i with multiple patterning, Extreme Ultraviolet Lithography and Directed Self Assembly are viable contenders to enable scaling for future technology nodes. However each patterning technique comes with common challenges of ‘high initial pattern roughness’ and ‘etch resistance’, the correction/compensation of which becomes more critical as we work on smaller dimension features. Plasma Etch processes have the potential to improvise upon the incoming pattern roughness and improve LER/LWR downstream with enhanced selectivity to thinner resist for expediting sub 10nm technology development.

In this work we demonstrate the specific role of passivation control in the dual-frequency Capacitively Coupled Plasma (CCP) with thin ( EUV ) resist patterning as an example process to improve LER/LWR, resist selectivity and CD tunability for line/space patterns. We will draw the implicit trends between different passivation chemistry and their effectiveness for roughness improvement. The effect of relative C:F and C:H ratio in feed gas on CF_x and CH_x plasma species and in turn the evolution of pattern roughness is drawn. Data that evinces the role of plasma etch parameters impacting the key patterning metrics of CD, resist selectivity and LER/LWR will be presented.