Diode chip structure and manufacturing method

Abstract

The invention discloses a diode chip manufacturing method. According to the method, at least one epitaxial layer is formed on a substrate; a groove region is formed on the epitaxial layer; ion implantation and diffusion are carried out through a first process condition, so that a first well region corresponding to the transverse PN junction is formed in the groove region, a second well region corresponding to the longitudinal PN junction is formed on the epitaxial layer, and a plurality of third well regions used for terminal ring regions are formed on the epitaxial layer; multiple times of ion implantation and diffusion are conducted under different process conditions so as to longitudinally form doped regions with different concentrations in the three well regions respectively; and a subsequent process is conducted to complete the manufacturing of the diode chip. The invention further discloses a diode chip structure. The technology is simple in process, the manufactured diode chip structure is smaller in size, the slow recovery characteristic is better, and the overshoot voltage at the cut-off moment of the MOS tube electrically connected with the diode chip structure can be greatly reduced in the flyback converter.

Description

technical field [0001] The invention relates to the technical field of semiconductor devices, in particular to a diode chip structure and a manufacturing method. Background technique [0002] Flyback converter is also called single-ended flyback converter. It gets its name because the output terminal gets energy when the primary winding is disconnected from the power supply. The flyback converter is popular among development engineers because of its simple circuit structure and low cost. A conventional flyback converter circuit such as figure 1 As shown, the disadvantage of this circuit is: due to the influence of component parasitic parameters, ringing and overshoot will occur at the drain of the switch tube, which will increase the pressure of the MOS tube and increase the loss. The ringing is caused by the oscillation circuit composed of leakage inductance Lleak, Rclp and Clump when the MOS is turned off. [0003] The traditional method of suppressing ringing is: in ...

AI Technical Summary

Problems solved by technology

The conventional flyback converter circuit is shown in Figure 1 The disadvantage of this circuit is that due to the influence of component parasitic parameters, ringing and overshoot will occur at the drain of the switch tube, resulting in increased pressure on the MOS tube and increased loss

These two methods can effectively suppress the ringing, but both will significantly increase the overshoot voltage at the moment of cut-off of the MOS tube

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