US 12,255,097 B2
Splash resistant laser wafer singulation by crack length control
Yang Liu, Sichuan (CN); Hao Zhang, Sichuan (CN); Venkataramanan Kalyanaraman, Allen, TX (US); Joseph O Liu, Plano, TX (US); Qing Ran, Sichuan (CN); Yuan Zhang, Sichuan (CN); Gelline Joyce Untalan Vargas, Marikina (PH); and Jeniffer Otero Aspuria, Baguio (PH)
Assigned to TEXAS INSTRUMENTS INCORPORATED, Dallas, TX (US)
Filed by Texas Instruments Incorporated, Dallas, TX (US)
Filed on Nov. 30, 2021, as Appl. No. 17/537,883.
Prior Publication US 2023/0170257 A1, Jun. 1, 2023
Int. Cl. H01L 21/78 (2006.01); B23K 26/38 (2014.01); H01L 21/66 (2006.01); H01L 21/67 (2006.01); H01L 23/00 (2006.01); H01L 23/544 (2006.01); B23K 101/40 (2006.01)
CPC H01L 21/78 (2013.01) [B23K 26/38 (2013.01); H01L 21/67115 (2013.01); H01L 21/67288 (2013.01); H01L 22/12 (2013.01); H01L 23/544 (2013.01); H01L 23/562 (2013.01); B23K 2101/40 (2018.08)] 21 Claims
OG exemplary drawing
 
1. A method of dicing a semiconductor wafer, comprising:
positioning the semiconductor wafer having a top side and a bottom side with the top side on a tape material, wherein the semiconductor wafer has at least a semiconductor surface on the top side including a plurality of die comprising circuitry that are separated by scribe streets;
directing a first pass comprising a first infrared (IR) laser beam at the bottom side with a point of entry within the scribe streets, wherein the first IR laser beam is focused with a focus point embedded within a thickness of the semiconductor wafer, wherein parameters for the first IR laser beam are selected so that there is an embedded crack line formed within the semiconductor wafer, and wherein the embedded crack line does not reach a surface of the top side;
directing a second pass comprising a second IR laser beam at the bottom side, wherein parameters for the second IR laser beam are selected to form a second crack line that has a spacing in a vertical direction relative to the embedded crack line, and the second IR laser beam causes the embedded crack line to be extended by a crack extension to reach the surface of the top side, wherein the spacing between the embedded crack line and the second crack line in the vertical direction is between 18 μm and 60 μm.