- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Advances in thermal laser separation: process monitoring in a kerf-free laser-based cutting technology to ensure high yield
摘要： Thermal Laser Separation (TLS) is an ablation free and therefore kerf free laser based cutting technology. This novel dicing technology is utilized to separate microelectronic devices on semiconductor wafers. In order to broaden the use of TLS method towards smaller chips and new materials on the one side and towards an advanced process monitoring on the other side, a novel contact-free measuring method for monitoring the TLS process has been developed. This new method is based on heating the semiconductor wafer with a near-infrared (NIR) laser and analyzing the subsequent temperature gradients induced by heat diffusion with contact-less temperature measurement. Thus, the TLS-crack can be detected due to its isolating effect to heat flux. The feasibility of the method is presented and the influence of parameters like sample size, distance to the TLS-crack and the laser setup in the measurements is reported.
关键词： kerf-free laser-cutting technology,cut detection,Laser dicing,Thermal Laser Separation,process monitoring
更新于2025-09-11 14:15:04
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(111)Si thin layers detachment by stress-induced spallation
摘要： In this work, results of controlled detachment of (111) silicon by stress induced spalling (SIS) process, which is based on a gluing on a metallic stressor layer by an epoxy adhesive on top of a silicon substrate, are presented. It is shown that silicon foils mainly (1x1) cm2 with different thicknesses (~50-170 μm) can be successfully detached using different materials (steel, copper, aluminum, nickel and titanium) as stressor layers with thicknesses ~50-500 μm. Such detachment can be realized by dipping of a stressor/glue/silicon wafer based structure into liquid nitrogen. As a result, Si foils with different thicknesses from ~50 μm to ~170 μm can be detached. An analytical and numerical approaches based on principles of linear elastic fracture mechanics is developed and they are shown that such approaches can predict general trends and conditions for the detachment of silicon foils with desired thicknesses using a stressor layer. Raman spectroscopy analysis of the residual stresses in detached silicon foils shows, that tensile stresses (up to - 36MPa) as well as higher value compressive stresses (up to ~444 MPa) are present in such foils. Moreover, optical and scanning electron microscopy (SEM) measurements show that surface of the detached foils exhibits some periodic lines originated by stresses.
关键词： Exfoliation of silicon,Thermal stress,Raman spectroscopy,Kerf-free,photovoltaics (PV)
更新于2025-09-09 09:28:46