Laser induced simultaneous etching of silicon and deposition of carbon materials

Abstract

Silicon (100) substrates have been irradiated in a gaseous atmosphere of diiodo-methane (CH2I2) by employing two different types of laser sources. Either focused 248nm excimer laser pulses or 532nm cw laser radiation have been used. Below the melting temperature of Si, complex etching of Si and deposition of carbon appear simultaneously only for irradiation with 248nm. Above the Si-melting point, the precursor allows efficient etching of Si with a simultaneous deposition of carbon materials for both wavelengths. In particular with focused 532nm radiation high processing rates and aspect ratios of the structures can be achieved.