Open AccessWater in contact with the backside of a silicon substrate enables drilling of high-quality holes through the substrate using ultrashort laser pulses
Author(s) -
Miku J. Laakso,
Simone Pagliano,
Umer Shah,
Gustaf Mårtensson,
Göran Stemme,
Frank Niklaus
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.377256
Subject(s) - laser drilling , drilling , silicon , materials science , substrate (aquarium) , etching (microfabrication) , laser , optoelectronics , optics , nanotechnology , metallurgy , geology , oceanography , physics , layer (electronics)
Holes through silicon substrates are used in silicon microsystems, for example in vertical electrical interconnects. In comparison to deep reactive ion etching, laser drilling is a versatile method for forming these holes, but laser drilling suffers from poor hole quality. In this article, water is used in the silicon drilling process to remove debris and the shape deformations of the holes. Water is introduced into the drilling process through the backside of the substrate to minimize negative effects to the drilling process. Drilling of inclined holes is also demonstrated. The inclined holes could find applications in radio frequency devices.