One challenge for volume manufacturing of 4H-SiC devices is the state-of-the-art wafer dicing technology – the mechanical blade dicing which suffers from high tool wear and low feed rates. In this paper we discuss Thermal Laser Separation (TLS) as a novel dicing technology for large scale production of SiC devices. We compare the latest TLS experimental data resulting from fully processed 4H-SiC wafers with results obtained by mechanical dicing technology. Especially typical product relevant features like process control monitoring (PCM) structures and backside metallization, quality of diced SiC-devices as well as productivity are considered. It could be shown that with feed rates up to two orders of magnitude higher than state-of-the-art, no tool wear and high quality of diced chips, TLS has a very promising potential to fulfill the demands of volume manufacturing of 4H-SiC devices.

This paper presents improvements in resizing single crystalline Si wafers by using the dicing technology "Thermal Laser Separation" (TLS). Results of this work support the general need to resize wafers to smaller diameters and will play an important role during the transition to larger wafer diameters as currently projected in the ITRS for 450 mm: Wafers of new sizes have to be easily adapted to fit, e.g., currently available metrology tools. TLS process parameters were developed for resizing Si wafers and to produce demo wafers which were analyzed and compared with current state of the art techniques plasma etching, laser ablation and mechanical wafer sawing. For the first time, circular cuts with diameters up to 300 mm were produced out of 450 mm ( thickness: 925 mu m) single crystalline Si wafers with TLS. The TLS process results in two important benefits for resized wafers: First, the edge of the new wafer is of higher quality than the edges produced by state of the art resizing techniques. Second, the TLS process is up to 24 times faster than known resizing processes

No abstract

Based on recent progress on laser-based wafer dicing equipment and process, the partners adixen, Fraunhofer IISB and JENOPTIK investigated the use of a vacuum based decontamination process to dry and to decontaminate the substrate surface of the diced wafers from water residuals, which are a side-effect of the TLS (thermal laser separation) approach. The decontamination process was achieved by using an adixen vacuum drying module prototype further to the JENOPTIK TLS dicing process. Within the frame of the European collaborative project SEAL, supported by the European Commission, experimental assessment was conducted by Fraunhofer IISB (research institution) together with JENOPTIK and Adixen.

Mechanical blade dicing is a state-of-the-art technique for the chip separation of SiC devices. Due to the hardness of SiC this technique suffers from low feed rate and high wear of the diamond coated dicing blade, resulting in the risk of uncontrolled tool breakage during the dicing process. With the upcoming transition to 150 mm diameter of SiC wafers this technique will most probably reach its limit. For dicing SiC wafers of those diameters on a productive scale three alternative dicing technologies are considered in this paper: ablation laser dicing, Stealth Dicing and Thermal Laser Separation. All these methods are based on laser processing. The benefits of these technologies are discussed in detail and compared to the classical mechanical diamond blade dicing, including a brief summary of first experimental results on each of the three laser dicing technologies.