DISCO Corporation (Head Office: Ota-ku, Tokyo; President: Kazuma Sekiya) has developed KABRA!zen, which achieves the full-automatization of the KABRA process: an ingot slicing method which uses a laser. This equipment enables a series of processes required in the KABRA process, including laser irradiation, wafer separation, fine grinding down to the designated thickness, and grinding of the top surface of the ingot, all unmanned, further accelerating advances in the efficiency of SiC wafer production. KABRA!zen will be exhibited in SEMICON Japan, held at Tokyo Big Sight from December 13 to 15. DISCO has already received inquiries from major wafer manufacturing companies and is aiming to ship test equipment within 2018.
*1 Trademark pending
*2 Total 53 of patents, including pending patents (as of December 11) / trademark registered (number 5850324)
*3 By continuously irradiating the laser vertically from the upper surface of the ingot, a separating layer that absorbs light is formed into a flat shape at the desired depth, developing an unprecedented slicing processing method of peeling and forming wafers from this point. KABRA stands for Key Amorphous-Black Repetitive Absorption. For details, please visit the KABRA process site.
Because the existing KABRA process requires an operator to remount workpieces before each process (including laser irradiation, wafer separation, fine grinding down to the designated thickness, and grinding of the top surface of the ingot), the throughput was affected by the ability of the operator. Furthermore, it is predicted that there will be an increase in electric power consumption across a wide range of products due to the development of the IoT and the use of electronics in vehicles, and there are expectations for the widespread use of energy-saving power devices which use next generation-materials, such as SiC. However, in the conventional diamond wire saw ingot slicing method, a low throughput and a large amount of material loss during processing was causing an increase in manufacturing costs.
Fully-automatic transfer between processes achieves approx. 50% increase in
The throughput has been drastically improved through the full-automatization of transfers between each process: laser irradiation, wafer separation, fine grinding down to the designated thickness, and grinding of the top surface of the ingot.
Table1. Advantages of KABRA!zen
|Existing process*4・5Wire saw + Lapping grind||KABRA!zen*6Fully automatic process|
|Slicing time||4–5 days||17 minutes (Laser irradiation + separation)|
|Material loss (per wafer)||Approx. 300 µm||Approx. 100 µm|
|During slicing||Approx. 200 µm||0 µm|
|During grinding||Approx. 100 µm||Approx. 100 µm|
|Number of wafers produced from three ingots||183 wafers||264 wafers|
|Processing time per wafer||31–39 minutes||15 minutes|
|Lapping grind||16 hours (simultaneous processing of multiple workpieces)||Not required|
|Total processing time for three ingots||4–5 days||2.75 days*7|
|Number of ingots required to produce 10,000 wafers||164||114|
|Number of days required to produce 10,000 wafers*8||219–273 days||104 days|
*4 When wafers with the designated thickness of 350 µm are produced from an SiC ingot with a diameter of
Φ6 inches and a thickness of 40 mm (No. of ingots: 3)
*5 When a lapping grind is performed after cutting using a loose abrasive-type diamond wire saw (200 multi-loop wire). All values are standard values based on the values acquired from users.
*6 These are the values at the time of issuing this press release.
*7 Ingot surface grinding, laser irradiation, and wafer separation are performed in parallel.
*8 Operational time calculated at 24 hours per day
Customization of the number of connected machines
Because the system joins each of the laser, separation, and grinding processes, the number of machines used for each process can be customized according to the various criteria, such as the number of wafers produced, surface finish condition, etc.
Full-automatization possible through retrofit
Even if you are currently using the preceding, manual KABRA equipment (DAL7420), full-automatization of your existing equipment is possible through a retrofit.
The fully-automatic process and all equipment used in the KABRA!zen process (to be exhibited at SEMICON Japan 2017) are developed by DISCO.
Number of Related Patents: 53 *Including pending patents (as of December 11, 2017)
Breakdown: 13 process-related patents, 3 full-automatization (KABRA!zen) patents, 19 laser irradiation patents, 7 separation patents, 2 grinding patents, 9 miscellaneous patents
The equipment was designed assuming full auto mass production for SiC Epi Ready wafers*9using KABRA!zen. (E.g.)
①Ingot coarse grinding
②Ingot fine grinding
⑤Wafer edge trimming
⑥Wafer coarse grinding
⑦Wafer fine grinding
⑨Wafer polishing (Both sides)
⑩Wafer fine polishing (Si surface)
*9:Wafers polished to high quality before thin film crystals are grown (epitaxial growth) on the surface. Because crystal defects generated during ingot growth may affect device characteristics, it is necessary to grow a thin crystal layer (epi layer) without defects on the wafer surface.
|December 13–15, 2017||SEMICON Japan 2017 (reference exhibit)|
|Within 2018 (estimate)||First shipment to customer|
*As of December 11, 2017
Japanese published, unexamined patent publication nos. 2015-223589, 2016-062949, 2016-111143, 2016-111144, 2016-111145, 2016-111146, 2016-111147, 2016-111148, 2016-111149, 2016-111150, 2016-124015, 2016-127186, 2016-146446, 2016-146447, 2016-146448, 2016-151457, 2016-197698, 2016-197699, 2016-197700, 2016-207702, 2016-207703, 2016-225535, 2016-225536, 2017-005008, 2017-022283, 2017-024014, 2017-024039, 2017-024188, 2017-028072, 2017-041481, 2017-041482, 2017-057103, 2017-092314, 2017-121742, 2017-123405, 2017-188586, 2017-189870, 2017-216424 Patent application nos. 2016-116126, 2016-157879, 2016-166476, 2016-190952, 2016-234958, 2016-236701, 2017-013073, 2017-015742, 2017-027113, 2017-027114, 2017-038435, 2017-086074, 2017-113391, 2017-128507, 2017-221073