Device and method for monitoring laser energy density

Abstract

The invention discloses a monitoring device and method for laser energy density. The device comprises: a pattern monitoring and acquisition module, which is used to detect and collect micro-grains generated on the surface of a silicon wafer during the annealing process; a pattern control module, which monitors the pattern The micro-pattern collected by the acquisition module is processed and stored to obtain the actual energy density corresponding to the micro-pattern; the host circuit module directly obtains the actual energy density of the micro-pattern obtained from the graphic control module and the laser Calculate the energy density of the laser, and adjust the energy density of the laser to the best according to the calculation results. By adopting the monitoring device and method of the present invention, the silicon wafer after laser annealing will not be damaged due to the influence of ion implantation, but real-time monitoring and compensation can be realized, greatly saving cost and improving yield. By monitoring the micro-grain on the surface of the silicon wafer, the output energy density of the laser is adjusted to make the silicon wafer at the optimum process energy density, which improves the yield rate of the process.

Description

technical field [0001] The invention relates to the field of integrated circuit manufacturing, in particular to a monitoring device and method for laser energy density. Background technique [0002] IGBT (Insulated Gate Bipolar Transistor, Insulated Gate Bipolar Transistor) is mainly used in high voltage and high current devices. At present, IGBTs are mainly used in induction cookers and rice cookers in the field of home appliances, in servo drives, subway heads, and high-speed locomotives in the automotive field, and in a series of high-power devices such as motor control and industrial frequency converters in the industrial field. [0003] The main reason why the device can withstand high voltage is that it has a thicker N layer. The optimal production method is to directly fabricate the upper structure of the IGBT high-voltage power device on the N-type silicon wafer substrate, and then thin the wafer. The thickness of the N layer is controlled, and finally the backside ...

AI Technical Summary

Problems solved by technology

At present, to detect whether the laser energy density changes during the annealing process, the extended resistance probe technology is mainly used to test the resistance value of the fixed test point through four probes to evaluate whether the energy density is stable. The wafer surface is damaged and affected by the ion implantation process

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