Short-wave infrared looks at solar wafers

這一篇文章主要描述使用SWIR(短波紅外線，比近紅外線波長還要長)技術加上InGaAs相機的需求越來越多。Sensors Unlimited Goodrich ISR Systems這家公司專門提供NIR/SWIR的InGaAs相機。

重點摘要:

At SWIR wavelengths, silicon becomes transparent. Since circuits are created on a wafer's front side, InGaAs sensors can create images of these circuit patterns on crystalline-silicon PV wafers and standard silicon wafers through their back sides, to determine whether they are aligned properly and to find cracks and voids, said Malchow. "When finished crystalline PV solar cells are connected to a power supply and voltage is forced into them, it creates an electroluminescent glow that can be imaged to find cracks, dead spots, contaminants, and weak areas," he said.

InGaAs linescan or area cameras can be used in conjunction with an IR microscope to inspect very fine detail in surface or buried layers of standard silicon wafers, said Malchow, as well as to give a rough measure of layer thicknesses. For those who need to inspect wafers at very high speeds, the new Goodrich SU1024LDH2 linescan camera will reach line rates of over 91,000 lines/s, reducing exposure times. "Our cameras are also used for examining structures inside MEMS devices, to ensure that nothing is left from the process to obstruct movement," he said.

詳情請見:
http://www.tmworld.com/article/457139-Short_wave_infrared_looks_at_solar_wafers.php