Redistribution method of heavy doping boron silicon slice

Abstract

The invention provides a redistribution method of a heavy doping boron silicon slice, and relates to a heavy doping boron silicon slice. The heavy doping boron silicon slice is placed on a tray, and then placed in a quartz chamber. The door of a screening box is closed. A seal mechanism is rotated and pressed tightly. The quartz chamber is vacuumized. Redistribution required gas is fed in the quartz chamber through a gas inlet and a gas outlet. The power is turned on. An electric field is applied in the space through an electrode slice. A radio-frequency power supply is started. The load matching is realized by an automatic matching unit, so that an induction coil produces a high-frequency changing magnetic field. A temperature sensor is started. The input power is adjusted to reach a required temperature by using the temperature indication of the temperature sensor. The heavy doping boron silicon slice is heated and the redistribution process starts. For ensuring operator safety, an electromagnetic shielding outer shell is arranged outside the electromagnetic induction coil. In the whole process of redistribution, an interference field strength meter is turned on to monitor field strength in a real-time manner, so that the field strength is within a relatively regulated range. The heating rate is fast, the cost is low, and the residual stress is effectively reduced.

Description

technical field [0001] The invention relates to a heavily doped boron-silicon chip, in particular to a method for redistributing a silicon chip after being heavily doped with boron by using a radio frequency induction heating diffusion method in a micro-electromechanical system (MEMS). Background technique [0002] In MEMS processing technology, the combination of heavy doping process and self-stop etching process with good controllability can accurately prepare borosilicate film with a thickness of several microns to tens of microns, which can be used as the structural layer of micro devices (such as pressure membranes, cantilever beams, etc.). Due to the size requirements of the structural layer, it is usually necessary to use thermal diffusion for high-concentration deep doping. In the thermal diffusion process, in order to obtain a deeper heavily doped layer, two-step diffusion is usually required—pre-diffusion and redistribution. [0003] For redistribution, the usual...

AI Technical Summary

Problems solved by technology

Due to the temperature limit of the quartz tube, it is difficult to apply a long-term high temperature above 1200 °C

Therefore, when a higher redistribution temperature is required, only expensive silicon carbide furnace tubes can be used, and the preparation cost is greatly increased.

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