Patent ID: 6916671

Claim:
A apparatus for measuring a gate oxide thickness, which is disposed in a scribe line region, comprising: a first active area disposed on a substrate, a width of the first active area is a predetermined width of at least 2F; first to fifth wordlines disposed on the substrate in a first direction, with a first predetermined space between each two wordlines, and the first ends of the first to fifth wordlines are electrically connected; first and second bar-shaped trench capacitors disposed under the second and the fourth wordlines respectively, with a second predetermined space between the first and second bar-shaped trench capacitors, the first and second bar-shaped trench capacitors are longer than the first active area; wherein the first space is smaller than the second space, and F is a minimum line width of the wordlines; and first and second gate structures respectively disposed between the first bar-shaped trench capacitor and the second wordline and between the second bar-shaped trench capacitor and the fourth wordline, each gate structure comprising a gate conducting layer and a gate oxide layer, wherein the gate conducting layers are electrically connected to the wordlines respectively.