Autofocusing of laser lithography through the crosshair projection method

• DOI: 10.1364/ao.523160
• Publication Date: 2024-04-25T17:00:09Z
• Authors: Wei Wei; Jingsong Wei; Tianyu Gao; Xiaozhong Xu
• Keywords: Reticle; Sample (material); Position (finance); Feature (linguistics); Image plane

In laser direct writing lithography, there is not any image information from the sample surface, which makes it difficult to find position of focal plane. To overcome problem, an autofocusing through crosshair projection method proposed in this work. The on reticle inserted into lighting path and imaged onto surface. addition increases meeting requirement for focusing improving environment. Furthermore, work presents what we believe be a new division curve based range perpendicular feature extracted during process. can zone but flat zone. Compared with traditional division, enables use directly determine current This completely filter out interference local fluctuations zone, greatly facilitating focusing. process was designed experiments were carried accordingly. accuracy about 0.15 µm, depth focus optical system. results show that provides good solution achieve accurate surface lithography.