Cohesive behavior of single crystalline silicon carbide scribing by nanosecond laser

Abstract

The existing mechanical dicing process of single crystalline Silicon Carbide (SiC) is one of the main factors limiting the development of semiconductor process, which could be replaced by laser scribing potentially. To achieve efficient and low-damage SiC separation, the cracking behavior of SiC after laser grooving should be well understood and controllable. Since the laser grooving including thermal ablation and meltage solidification, the cracking behavior of the scribed SiC would be different to the original single crystal SiC. In this paper, cohesive zone model (CZM) is used to quantitively represent the cracking behavior of the nano-laser scribed SiC. The separation after scribing was conducted in a three-point bending (3 PB) fixture to characterize the cracking behavior. Therefore, by inverting the load–displacement curves of 3 PB with CZM embedded finite element model, the cohesive behavior is characterized by bilinear traction–separation law, which illustrated the whole cracking process numerically. The methodology established in current paper gives way to understand the SiC scribing and cracking process with quantitative cohesive parameters.