Measurement of trench depth by infrared interferometry.
Measurement and control of high-aspect-ratio structures such as dynamic random-access memory trenches is an important step in the manufacture of modern memory devices. We present a novel technique based on infrared interferometry that has been implemented in manufacturing and is capable of measuring sub- 0.25-mum -wide and 10-mum -deep trenches nondestructively and with an accuracy of better than 0.1mum .
van Kessel
T
T
Wickramasinghe
H K
HK