2results about How to "Adjust threshold voltage" patented technology

The invention belongs to the technical field of power devices, and provides a silicon carbide power device capable of improving threshold voltage degradation, a preparation method thereof and a chip, a reinforcing layer and a P-type polycrystalline silicon layer are formed in a gate dielectric layer, the reinforcing layer is located above a junction field effect region, the width of the reinforcing layer is equal to or larger than that of the junction field effect region, the reinforcing layer is introduced, and the threshold voltage degradation is improved. The thickness of the insulating layer is improved, the tunneling probability of carriers in the device is reduced, the electron tunneling potential barrier of the device and the tunneling probability of the carriers in the junction field effect region are improved through the P-type polycrystalline silicon layer, the hole concentration of a channel is reduced through the adjusting layer, and the threshold voltage of the device is adjusted.

A method for forming a semiconductor structure, the method comprising: providing a substrate comprising a first region and a second region, and forming an interlayer dielectric layer having a gate opening on the substrate; forming a shielding layer covering the gate opening of the second region and exposing the gate opening of the first region, the shielding layer occupying the gate opening of the second region, so that in the step of forming a first work function material layer in the gate opening of the first region, the first work function material layer is formed on the shielding layer, and in the process of removing the shielding layer and the first work function material layer on the shielding layer, the removal process window of the first work function material layer of the second region is larger, and it is not easy to have residues, and the removal efficiency is higher, which is beneficial to improve the yield; in addition, the removal process window of the shielding layer is larger, and it is not easy to have residues, the second work function layer can better adjust the threshold voltage of the transistor of the second region, reduce the parasitic capacitance in the transistor of the second region, so that the electrical performance of the semiconductor structure is better.