The invention discloses a
wafer scribing process, which comprises the following steps of: amplifying the
line width of a saw street dummy
copper conductor and continuously filling to form a shearing buffer
copper strip; performing double-pulse
laser annealing on the shear buffer
copper strip to generate a twin
crystal softening layer; back
infrared gradient preheating is carried out according to the
thermoplastic transition temperature of the copper strip, the feeding rate and the rotating speed of a tool are corrected in combination with vibration data
coupling, and a plastic initial saw kerf is obtained; layering progressive deep
cutting is carried out according to multi-
gear cutting depth data, so that the copper strip slides to absorb energy under the
pulse load and is elastically reset through a low
dielectric layer, and a full-depth saw kerf is formed; and performing constant-temperature
crystal locking and gradient cooling in a
nitrogen environment, so that the twin
crystal structure of the copper strip is stable and is interlocked with the
dielectric layer shrinkage hoop, and a flexible bridging unit is generated on the side wall of the saw kerf. According to the technical scheme, the
interlaminar shear stress can be subjected to peak clipping and
shunting at the
cutting moment, selective layering of a multi-layer
interconnection interface is inhibited, and the yield and long-term reliability of the ultrathin
wafer are improved.