Samsung Electronics Co., Ltd.

Do-Yul Yoo

Jong-hyon Ahn

Dong-hun Lee

Sung-Gun Kang

Ji-Yong You

Joong-Sung Kim

Hyung-Joo Youn

In an overlay key used for measuring overlay accuracy between first and second layers on a substrate, a first mark may be formed in the first layer, and a second mark may be formed on the second layer. The first mark may include first patterns having a first pitch and extending in a first direction. The second mark may include second patterns extending in substantially the same direction as the first direction and having a second pitch substantially equal to the first pitch. First and second images may be acquired from the first and second marks. The overlay accuracy may be produced from position information of first and second interference fringes formed by overlaying a test image having a third pitch onto the first and second images.

Overlay key, method of forming the overlay key and method of measuring overlay accuracy using the overlay key

Provided are a photomask and a method of fabricating a semiconductor device. The photomask includes a photomask substrate including a chip region and a scribe lane region, with an overlay mark formed in the scribe lane region. The overlay mark includes one or more sub-overlay marks. Each of the sub-overlay marks includes a plurality of unit regions sequentially connected to each other and having different widths, where the width of a given unit region is constant.

Photomask with overlay mark and method of fabricating semiconductor device

An overlay mark includes at least one hole array formed on a semiconductor substrate and at least one linear trench adjacent to the hole array. The hole array may be formed adjacent to the linear trench along a predetermined direction. When alignment errors among patterns formed at predetermined portion of the semiconductor substrate are detected, the overlay mark may provide a contrast of light with a desired width and a high level so that alignment errors of patterns formed on the semiconductor substrate may be accurately detected and corrected using the overlay mark.

Overlay mark for measuring and correcting alignment errors

An overlay key includes a main scale and a vernier scale, which traverse each other forming a plurality of crossings. The main scale includes a first main sub-scale and a second main sub-scale, which are separated from each other or at least partially overlap each other. The first and second main sub-scales extend in different directions such that they are not parallel to each other. The vernier scale includes a first vernier sub-scale and a second vernier sub-scale, which are separated from each other or at least partially overlap each other. The first and second vernier sub-scales extend in different directions such that they are not parallel to each other. Two measured crossings are obtained when the main scale and the vernier scale cross each other in a measured position. Then, overlay accuracy is measured from coordinate differences between reference crossings and the measured crossings.

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Gyeonggi-do, South Korea

Do-Yul Yoo