ホーム > 製品紹介 > GaAs基板 > その他仕様

その他仕様

Flatness・Light Point Defects / Categories of Off-Orientation

Flatness

Flatness

Definitions of Flatness

TTV Total Thickness Variation:
The difference between the highest and the lowest elevation of the top surface of a clamped wafer.
The back surface referenced.
TIR Total Indicated Reading:
The difference between the highest point above and the lowest point below the front surface referenced focal plane of a clamped wafer. 3 points on the front surface generally used.
LTV Local Thickness Variation:
The difference between the highest point and the lowest point within a site of the top surface of a clamped wafer.
The back surface referenced.
PLTV Percent LTV:
Percentage of sites on a wafer within the specified LTV value.
Warp The difference between the highest point above and the lowest point below the front surface referenced focal plane of an unclamped wafer.
A least square fit on the front surface generally used.

Light Point Defects

Light Point Defects

Clockwise (EJ) / Counter Clockwise (US)

Clockwise (EJ) / Counter Clockwise (US)

Planar Representation of Cubic Form

Planar Representation of Cubic Form

Example of off-orientation

Example of off-orientation

カタログ一覧 (GaAs基板)

ページの先頭へ