公开(公告)号：US20170108329A1

公开(公告)日：2017-04-20

申请号：US15206613

申请日：2016-07-11

Applicant: Samsung Electronics Co., Ltd.

Inventor： KWANG-SOO KIM ,  Harutaka SEKIYA ,  Kwang-jun YOON ,  Sung-won PARK ,  Young-duk KIM ,  Heon-ju SHIN ,  Byeong-hwan JEON

IPC: G01B11/00 ,  G01N21/01 ,  G01N21/956 ,  H01L21/68 ,  G01N21/95

CPC classification number: G01B11/002 ,  G01N21/9501 ,  G01N21/956 ,  G01N2201/121 ,  H01L21/681

Abstract: An automatic focus control apparatus includes a light detector, which receives light reflected by a surface of a wafer and generates a light reception signal based on the received signal, a controller, which generates a driving signal, the driving signal being one of a first signal and a second signal, the driving signal indicating whether to perform automatic focus control based on the light reception signal, a focus error corrector, which generates a focus error correction signal based on the driving signal, and a stage driver, which displaces a wafer stage supporting the wafer by adjusting the z-axis position of the wafer stage based on the focus error correcting signal if the driving signal is the first signal, and maintains the z-axis position of the wafer stage based on the focus error correction signal if the driving signal is the second signal.