Field-stop reverse conducting insulated gate bipolar transistor and manufacturing method therefor
地域：
Jiangsu
摘要
A field-stop reverse conducting insulated gate bipolar transistor and a manufacturing method therefor. The transistor comprises a terminal structure (200) and an active region (100). An underlayment of the field-stop reverse conducting insulated gate bipolar transistor is an N-type underlayment, the back surface of the underlayment is provided with an N-type electric field stop layer (1), one surface of the electric field stop layer departing from the underlayment is provided with a back-surface P-type structure (10), and the surface of the back-surface P-type structure is provided with a back-surface metal layer (12). A plurality of notches (11) which penetrate through the back-surface P-type structure (10) from the back-surface metal layer (12) to the electric field stop layer (1) are formed in the active region (100), and metals of the back-surface metal layer (12) are filled into the notches (11) to form a metal structure which extends into the electric field stop layer (1).
說(shuō)明書(shū)
The present invention relates to a manufacturing method of a semiconductor device, and particularly relates to a field stop reverse conducting insulated gate bipolar transistor, and further relates to a manufacturing method of the field stop reverse conducting insulated gate bipolar transistor.
The insulated gate bipolar transistor (IGBT) is generally used in a manner of a reverse parallel freewheeling diode. However, on one hand, this manner results in waste of the package area; on the other hand, due to the existence of parasitic effects such as a parasitic inductor, the parallel additionally increases the power consumption. Therefore, the technology of integrating the IGBT and the diode in a same chip is increasingly emphasized.
The back side N+ type and the P+ type of the conventional reverse conducting insulated gate bipolar transistor (RC-IGBT) spread the whole back side of the IGBT. When turning on the diode, a large number of holes is injected via the positive pole (the emitter of the IGBT), a part of which come into the cathode through the N-drifting region of the terminal. When recovering reversing of the diode, the holes stored below the terminal cannot be empty and disappear quickly. The recovering characteristic of the diode has to be improved by the controlling technology for the carrier lifetime such as irradiation.
On the basis of this, it is necessary to provide a field stop reverse conducting insulated gate bipolar transistor having a better reverse recovering characteristic.
權(quán)利要求
What is claimed is:1. A field stop reverse conducting insulated gate bipolar transistor, comprising: a peripheral terminal structure and an active region surrounded by the terminal structure, a substrate of the field stop reverse conducting insulated gate bipolar transistor being an N-type substrate, a back side of the substrate being disposed with an N-type field stop layer, a side of the field stop layer away from the substrate being disposed with a back side P-type structure, a surface of the back side P-type structure away from the substrate being disposed with a back side metal layer;characterized in that, a plurality of notches are formed in the active region extending from the back side metal layer through the back side P-type structure into the field stop layer, a metal of the back side metal layer is filled in the plurality of notches to form a metal structure extending into the field stop layer, the plurality of notches and the metal structure extending into the field stop layer are not disposed in the terminal structure. 2. The field stop reverse conducting insulated gate bipolar transistor of claim 1 , characterized in that, a field limiting ring is disposed in the terminal structure at a front side of the substrate, a silicon oxide layer is disposed on the field limiting ring;a P well is disposed in the active region at the front side of the substrate, an N-type emitter is disposed in the P well, a gate oxide layer is disposed at the front side of the substrate, a polysilicon gate is disposed at a surface of the gate oxide layer, the polysilicon gate is covered by the silicon oxide layer, an emitter metal structure is disposed on the P well, the silicon oxide layer and the emitter metal structure are covered by a passivation layer. 3. The field stop reverse conducting insulated gate bipolar transistor of claim 2 , characterized in that, both the field stop layer and the emitter are the N+ type, the back side P-type structure is the P+ type. 4. The field stop reverse conducting insulated gate bipolar transistor of claim 1 , characterized in that, the back side metal layer and the metal structure extending into the field stop layer are aluminum-titanium-nickel-silver structures. 5. The field stop reverse conducting insulated gate bipolar transistor of claim 1 , characterized in that, the field stop reverse conducting insulated gate bipolar transistor is a plane gate insulated gate bipolar transistor. 6. A manufacturing method of a field stop reverse conducting insulated gate bipolar transistor, comprising the following steps:step A, providing an N-type substrate, regarding a side of the substrate as a back side, forming an N-type field stop layer at the back side; step B, performing a first phrase front side process; which comprising forming a high voltage-resisting structure at a terminal structure peripheral to a front side of the substrate of the field stop reverse conducting insulated gate bipolar transistor, forming a gate oxide layer at a front surface of a substrate of a active region area surrounded by the terminal structure, and forming a polysilicon gate at a surface of the gate oxide layer, forming a P well in the active region area at the front side of the substrate, forming an N-type emitter in the P well, forming a silicon oxide layer covering the front side of the substrate and the polysilicon gate; step C, forming a back side P-type structure at a side of the field stop layer away from the substrate; step D, performing a second phrase front side process; which comprising photoetching and etching the silicon oxide layer, forming a contact hole having a part of the P well and the emitter exposing, filling an emitter metal structure in the contact hole, forming a passivation layer covering the silicon oxide layer and the emitter metal structure; and step E, forming a plurality of notches in the active region area through the back side P-type structure into the field stop layer, and forming a back side metal layer, wherein the back side metal layer is filled in the plurality of notches to form a metal structure extending in the field stop layer. 7. The manufacturing method of the field stop reverse conducting insulated gate bipolar transistor of claim 6 , characterized in that, the step B comprises:implanting P-type dopant at the front side of the substrate by photoetching, after thermal diffusion, forming a field limiting ring as the high voltage-resisting structure; growing a field oxide layer at the front side of the substrate, and photoetching and etching the field oxide layer on the active region area; growing a gate oxide layer at the front side of the substrate, and forming a polysilicon layer at a surface of the gate oxide layer; removing a surplus part of the polysilicon layer and the gate oxide layer by photoetching and etching, and forming a polysilicon gate, and ion-implanting P-type dopant to the substrate by a self-aligning implantation process, forming the P well after driving-in; photoetching and implanting N-type dopant ions to the P well to form the emitter; depositing an oxide dielectric layer, the field oxide layer and the deposited oxide dielectric layer forming the silicon oxide layer covering the front side of the substrate and the polysilicon gate. 8. The manufacturing method of the field stop reverse conducting insulated gate bipolar transistor of claim 7 , characterized in that, in the step B, the step of growing the gate oxide layer at the front side of the substrate is to grow a gate oxide layer with a thickness of 600 angstrom to 1500 angstrom. 9. The manufacturing method of the field stop reverse conducting insulated gate bipolar transistor of claim 7 , characterized in that, the step E comprises forming a plurality of notches in the active region area through the back side P-type structure into the field stop layer by photoetching and etching, and forming the back side metal layer and the metal structure extending in the field stop layer by a sputtering process;both the field stop layer and the emitter are the N+ type, the back side P-type structure is the P+ type. 10. The manufacturing method of a field stop reverse conducting insulated gate bipolar transistor of claim 6 , characterized in that, prior to the step C, the method further comprises a step of forming a front side protecting layer on the silicon oxide layer; after the step C and prior to the step D, the method further comprises a step of removing the front side protecting layer.
意見(jiàn)反饋
使用該功能遇到問(wèn)題
該功能需要專(zhuān)業(yè)版企業(yè)版VIP權(quán)限，您可以：
您也可以聯(lián)系官方QQ: 2157717237 電話: 13264338900
PatentHub聯(lián)系方式
掃描加專(zhuān)利匯官方微信交流群
