METHOD OF FORMING CHIP BOUNDARIES FOR INLAID PHOTODETECTOR MODULES Russian patent published in 2014 - IPC H01L21/782 

FIELD: physics.

SUBSTANCE: method of forming chip boundaries for inlaid photodetector modules involves depositing a protective coating on the planar side of a device wafer, after which a laser is used for scribing and splitting the device wafer. The protective coating is deposited with a thickness which enables to absorb laser radiation with energy density lower than the melting threshold in the material of the protective coating and prevent its action on semiconductor material. Scribing, which forms the boundary, is carried out using a multiple-pass mode. In each pass, the speed of the device wafer is selected based on the condition that there are no large zones of molten material on the surface by covering light spots from pulsed radiation, and that there is no reduction of the width of the channel due to deposition of the melt. When scribing, a channel with a symmetrical V shape is formed by directing radiation at a normal to the surface of the device wafer and obtaining a channel with walls which form an obtuse angle α with the surface of the device wafer, or an asymmetrical V shape, by deviating the optical axis of the laser system which generates the required radiation for scribing from the normal to the surface of the device wafer in the transverse direction of the formed channel, thereby obtaining a channel with a wall on the side of the chip which forms an angle smaller than α but not more than 180°-α with the surface of the device wafer.

EFFECT: high efficiency of image transformation in an inlaid photodetector module and wider field of application thereof.

6 cl, 9 dwg, 2 ex