Lithography Glossary

Written by Chris Mack
Brought to you by the creators of PROLITH

G-Line
A line of the mercury spectrum corresponding to a wavelength of about 436nm.

Example: G-line steppers were the dominant lithography tools throughout the 1980s.

GDS II
An industry standard file format for mask layout information.

Example: When finished, the chip designer performed a final "tape out", saving the mask layout data into GDS II format for transmittance to the mask shop.

Glass Transition Temperature
The temperature (or the midpoint of the temperature range) at which a polymer makes a transition from behaving mostly like a solid to behaving mostly like a liquid.

Example: After prebake, the glass transition temperature of the resulting resist film is approximately equal to the prebake temperature.

Global Alignment
A method of alignment where the mask is aligned globally to the whole wafer (as opposed to filed-by-field alignment).

Example: Where applicable, global alignment is preferred due to its high throughput.