Abstract
When linewidths in optical lithography are reduced, proximity bias, defined here as isolated to dense linewidth offsets, can consume large parts of the CD budget. This paper describes the resist thickness influence on proximity bias. If reflective substrates are used, proximity bias shows a cyclic behaviour. This can be seen as secondary swing caused by the spatial location of the remnant standing wave which results in photo active compound (PAC) concentration differences near the surface after diffusion. PAC acts as a dissolution barrier and influences the CD, resulting in different proximity biases for different resist thicknesses. When low-reflective substrates are used, as is the case with bottom anti-reflective coatings (BARCs), standing waves are less pronounced. On BARC substrates, a constant proximity bias was found, both in i-line and deep UV.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
