Samsung Electronics Co., Ltd.

Samsung Sds Co., Ltd.

Jung Hwan Moon

Chang Ho Kim

Jae Yoon Kim

Sung Hee Lee

Jae Hoon Jeong

Hee Tae Yoon

Kyu-Baik Chang

Jae Ho Yang

Hyoun Chul Lim

Jung Hoon Bak

Min Kyoung Joo

Hyoun Chul Rim

A wafer defect test apparatus in which a defect prediction performance is improved and a simulation time is shortened is provided. The wafer defect test apparatus comprises a wafer variable generator which receives a first structural measurement data and a first process condition data of a first wafer, and a second structural measurement data and a second process condition data of a second wafer, generates a first process variable and a second process variable based on the first structural measurement data and the first process condition data, and generates a third process variable and a fourth process variable based on the second structural measurement data and the second process condition data, an abnormal wafer index generating circuit which generates a first wafer vector of the first process variable and second process variable, generates a second wafer vector of the third process variable and fourth process variable, calculates a first Euclidean distance between the first wafer vector and the second wafer vector, calculates a first Cosine distance between the first wafer vector and the second wafer vector, and generates a first abnormal wafer index of the first wafer based on a product of the first Euclidean distance and the first Cosine distance, and a prediction model generating circuit which receives a first characteristic variable which is a test result of the first wafer, and generates a wafer defect prediction model through a regression based on the first process variable, the second process variable, the first characteristic variable, and the first abnormal wafer index.

Wafer defect test apparatus, wafer defect test system, wafer test method and fabrication method of a wafer

Provided are a system and method for a video call. The system for a video call includes one or more terminals configured to transmit images obtained by capturing video call users, and a video call control server configured to generate a combined image by combining the images transmitted by the one or more terminals, and transmit the combined image to the terminals. Here, the respective images are rotated according to information on orientations sensed by the terminals, and combined into the combined image.

System and method for video call

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Seoul, South Korea

Jung Hwan Moon