Structure for adjusting built-in Rg of trench gate MOSFET
By setting contact holes and bumps in the trench gate MOSFET, the contact area between the polysilicon interconnect and the metal block is adjusted, solving the problem of inaccurate control of Rg and realizing precise control of Rg and expanding its application range.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-07
- Publication Date
- 2026-04-10
AI Technical Summary
In existing trench gate MOSFETs, the gate resistance (Rg) cannot be precisely controlled, leading to device failure and circuit abnormalities, which limits its applicability in different application scenarios.
By setting different numbers of contact holes and bumps in the trench gate MOSFET, the contact area between the polysilicon interconnect and the bumps on the metal block can be controlled, and the Rc-chain value can be adjusted to precisely control the size of Rg.
This enables precise control of Rg, expands the application range of trench gate MOSFETs, improves circuit stability and product quality, and reduces production costs.
Smart Images
Figure CN224111566U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of semiconductor chip, concretely is a structure of built -in Rg of regulation groove gate MOSFET. BACKGROUND
[0002] The groove gate MOSFET is a kind of MOSFET structure that gate is buried in matrix and forms vertical channel, since gate, source and drain all need to be connected to circuit, and the three are close, and the gate external port is generally polycrystalline material (cannot be directly connected to circuit, so a metal sheet for wiring needs to be set on polycrystalline), which leads to that three cannot be connected to circuit in narrow area at the same time, so the gate is guided to another part through polycrystalline channel, and a metal sheet is set and connected to circuit;And the main purpose of gate connection is to promote the transfer of electrons between source and drain, and Rg (gate resistance) is designed in the chip gate area, for suppressing surge current in the circuit, reducing output ringing;Rg (gate resistance) is divided into external Rg_ex and built-in Rg_in;Built-in Rg_in=Rlines+Rmetal+Rc-chain+Rps-chain, since the resistivity of metal layer is low (milliohm order), Rlines+Rmetal can be ignored, or the estimated value is very low;The contact hole 20 resistance Rc-chain of metal layer and PS (polycrystalline) connection, and the polycrystalline resistance Rps-chain of PS layer are estimated to be 2:3, and theoretically Rg value is 10-100ohm most suitable (according to different applications, the value needs to be adjusted);
[0003] If Rg is small, oscillation will occur, and gate oscillation will cause device failure and circuit abnormal failure. In severe cases, three states will occur, one is complete conduction, two is complete shutdown, and three is high resistance conduction, and then burnout due to serious heating.
[0004] Therefore, it is necessary to control the size of Rg value, and in general circuit design, the gate is connected to other positions of the chip through polycrystalline for power connection, and a long strip-shaped metal sheet is set on the polycrystalline for external circuit connection. Since the contact area between the metal sheet and the polycrystalline is large, the contact hole 20 resistance Rc-chain of the metal and the polycrystalline contact is large, and the general control method is to control the length of the polycrystalline in contact with the metal sheet, but the length is generally nanoscale, which cannot be accurately controlled, especially in different chip application scenarios, different Rg values are suitable for different application intervals, which leads to that the original product design is only suitable for a certain field, such as BMS (power management), but when applied to brushless motor, due to the limitation of slight Rg value deviation, it cannot be applied.
[0005] Therefore, there is a need for a structure for adjusting the built-in Rg of a trench gate MOSFET to solve the problem that the Rg in the trench gate MOSFET cannot be accurately controlled. Content of the utility model
[0006] In view of the deficiencies in the prior art, the utility model discloses a structure for adjusting the built-in Rg of a trench gate MOSFET, which controls the contact area of the polycrystalline connecting channel and the protrusion on the metal block by opening different numbers of contact holes. When there is only one contact hole, the Rc-chain value of the connection between the polycrystalline connecting channel and the protrusion on the metal block is the largest. When the number of contacts is gradually increased, that is, the contact area of the polycrystalline connecting channel and the protrusion on the metal block is increased, the Rc-chain value is gradually reduced. Thus, the size of Rc-chain is controlled by opening different numbers of contact holes.
[0007] The utility model discloses the above-mentioned technical purpose is realized through the following technical scheme: a structure for adjusting the built-in Rg of a trench gate MOSFET, which comprises a silicon bottom liner, an epitaxial layer and an insulating layer arranged continuously in a vertical direction from bottom to top and integrated with a chip body. A plurality of polycrystalline lead-out channels are arranged between the epitaxial layer and the insulating layer and are in communication with the gate on the chip body. The plurality of polycrystalline lead-out channels are in communication through a polycrystalline connecting channel. A plurality of contact holes in communication with the polycrystalline connecting channel are arranged through the insulating layer. A metal block is arranged on the insulating layer, and the metal block is provided with a protrusion that penetrates into the contact hole and abuts against the polycrystalline connecting channel. The metal block is connected to an external electrical signal.
[0008] By adopting the above technical scheme, the MOSFET transistor exists on the chip body. The gate on the MOSFET transistor is electrically connected to the polycrystalline connecting channel through the polycrystalline lead-out channel of the polycrystalline material. The protrusion on the metal block abuts against and is electrically connected to the polycrystalline connecting channel. The pin of the metal block is connected to the external environment, thereby completing the electrical connection of the gate on the MOSFET transistor. The size of Rc-chain can be controlled by controlling the number of contact holes and the protrusion, that is, the contact area of the metal block and the polycrystalline connecting channel, thereby accurately controlling the size of Rg and increasing the range of use.
[0009] The utility model further provides that each contact hole is a rectangular hole structure with equal size, and the protrusion fills the contact hole.
[0010] By adopting the above technical scheme, the size of each contact hole is equal, so that the degree of change of Rg can be accurately controlled when the contact holes are increased or decreased, and the control effect of Rg value is further improved.
[0011] The utility model further sets up: the SRC source layer is provided with at the position of polycrystal connecting path and metal block contact, and the SRC source layer is the polycrystal structure of N type substance injection polycrystal connecting path.
[0012] By adopting the above technical scheme, according to the metal block of different materials, the concentration of the polycrystal in contact with the metal block is adjusted, and then the resistance stability when the metal block and the polycrystal are electrically connected is reduced, and the control precision of Rc-chain value is further increased.
[0013] The utility model further sets up: the SRC source layer on polycrystal connecting path and the source layer on chip body MOSFET transistor are located at the same layer.
[0014] By adopting the above technical scheme, when the SRC source layer on the polycrystal connecting path is doped with N type substance, the doping action on the source layer on the MOSFET transistor can be synchronized, and the control precision of Rc-chain value can be increased without increasing the process steps, the cost is reduced, and the control effect is increased.
[0015] The utility model further sets up: the metal on the source electrode on the metal block and chip body MOSFET transistor for electrically connecting the outside world is located at the same horizontal plane.
[0016] By adopting the above technical scheme, the external connection points of the gate electrode and the source electrode external circuit are located at the same height, the consistency of the external circuit is ensured, and the metal block and the metal can be installed and prepared under the same process, the process steps are reduced, and the cost is reduced.
[0017] In summary, the utility model has the following beneficial effects:
[0018] By controlling the contact area of the polycrystal and the metal outside the insulating layer on the polycrystal connecting path, the resistance value of the two is controlled, specifically, by controlling the number and size of the contact hole (controlling the number and size of the protrusion), the resistance value between the two is controlled, and then the value of the contact hole resistance (Rc-chain) is accurately controlled, further, the polycrystal in contact with the metal block is doped (doped with N type substance), to control the concentration of the polycrystal at this position, and then the stability of the metal block and the polycrystal connection resistance is increased, and the stability of the contact hole resistance is further increased. BRIEF DESCRIPTION OF DRAWINGS
[0019] Figure 1 It is a structural schematic diagram of the utility model;
[0020] Figure 2 It is a sectional view schematic diagram of one direction of the utility model;
[0021] Figure 3 It is a sectional view schematic diagram of one depth in horizontal direction of the utility model;
[0022] Figure 4 It is the cross section schematic view of the horizontal direction second depth of the utility model;
[0023] Figure 5 It is the structure schematic view of the polycrystal lead-out path, polycrystal connecting path, protrusion and metal block connection in the utility model;
[0024] Figure 6 It is Figure 2 It is the enlarged structure schematic view of A in the utility model.
[0025] In the drawing,
[0026] 14, metal block; 15, protrusion; 16, polycrystal connecting path; 17, silicon bottom lining; 18, epitaxial layer; 19, insulating layer; 20, contact hole; 21, SRC source layer; 22, polycrystal lead-out path. DETAILED DESCRIPTION
[0027] The utility model will be combined with the drawings in the embodiment of the utility model, and the utility model will be described in detail.
[0028] Embodiment:
[0029] The structure of the built-in Rg of the adjusting trench gate MOSFET, as Figures 1 to 4 Shown, including at least continuous setting along vertical direction from below to above and with the chip body is an integral part of silicon bottom lining 17, epitaxial layer 18 and insulating layer 19, epitaxial layer 18 and insulating layer 19 between being provided with a plurality of polycrystal lead-out path 22 with the gate communication on the chip body, and a plurality of polycrystal lead-out path 22 through polycrystal connecting path 16 intercommunication, insulating layer 19 on the through a plurality of polycrystal connecting path 16 intercommunication contact hole 20 is provided, insulating layer 19 on the metal block 14 is provided, and metal block 14 is provided with the protrusion 15 that goes down into contact hole 20 and with polycrystal connecting path 16 abuts, metal block 14 and external electric connection, each contact hole 20 is the rectangular hole structure of equal size, and protrusion 15 fills contact hole 20, polycrystal connecting path 16 and the position of metal block 14 contact is provided with SRC source layer 21, this SRC source layer 21 is the polycrystal structure of N type material injection of polycrystal connecting path 16, the SRC source layer 21 on polycrystal connecting path 16 and the source layer on the chip body MOSFET transistor is located in the same layer, and the metal on the chip body MOSFET transistor source for electrically connecting external is located in the same horizontal plane with metal block 14.
[0030] The utility model is an integral part of chip body, and the silicon bottom lining 17, epitaxial layer 18 and insulating layer 19 in the utility model are an integral part of the silicon bottom lining 17, epitaxial layer 18 and insulating layer 19 on the chip body,
[0031] First, the gates of multiple MOSFET transistors on the chip body are electrically connected to regions far from the MOSFET transistors via polycrystalline lead-out channels 22. Then, the multiple polycrystalline lead-out channels 22 are electrically connected to the metal block 14 via polycrystalline connection channels 16. Specifically, several first through-channels communicating with the gates of the MOSFET transistors and second through-channels communicating with the multiple first through-channels are formed on the epitaxial layer 18. Both the first and second through-channels are filled with polycrystalline material for conduction. An insulating layer 19 is then covered on top, thereby forming the polycrystalline lead-out channels 22 and the polycrystalline connection channels 16. Then, a connection channel is formed on the insulating layer 19 at the location of the polycrystalline connection channel 16 to the polycrystalline material in the second through-channel. A connected contact hole 20 is provided, and a metal block 14 is provided on the contact hole 20. The bottom of the metal block 14 is provided with a protrusion 15 that fills the contact hole 20 and abuts against the polycrystalline material in the second through groove. The metal block 14 can be used to complete the electrical connection between the external circuit and the polycrystalline connection channel 16, the polycrystalline lead-out channel 22 and the gate of the MOSFET transistor. It can also keep the position of the gate connected to the outside away from the position of the MOSFET transistor, leaving external space for the source and drain of the MOSFET transistor, thereby increasing its connection effect and preventing several electrical contact points from being concentrated in a narrow position, which would lead to unstable power connection or current turbulence, thereby increasing the use effect.
[0032] Furthermore, the current flows through the protrusions 15 on the metal block 14 to complete the current flow between the metal block 14 and the polycrystalline silicon. When there is only one protrusion 15, it can be regarded as three series with resistance values: the polycrystalline silicon, the protrusion 15, and the metal block 14. When there are many protrusions 15, it can be regarded as a series resistor between the polycrystalline silicon and the metal block 14, which is composed of several protrusions 15 in parallel. That is, the more protrusions 15 there are, the smaller the resistance between the polycrystalline silicon and the metal block 14. Moreover, there is a proportional relationship between the number of protrusions 15 and the resistance value between the polycrystalline silicon and the metal block 14. Therefore, the resistance value between the polycrystalline silicon and the metal block 14 can be precisely controlled by controlling the number of protrusions 15. The area of several contact holes 20 is the same (the cross-sectional area of the protrusions 15 is the same), which further increases the accuracy of controlling the resistance value by controlling the number of protrusions 15, that is, it can increase the control effect on Rg.
[0033] At the same time, by controlling the cross-sectional area of the contact hole 20 (i.e., controlling the contact area and volume between the protrusion 15 and the polycrystalline material), the calculation and control effect of the resistance value when increasing or decreasing the number of protrusions 15 can be further ensured, that is, the control effect of Rg can be increased.
[0034] Furthermore, N-type material is incorporated into the polycrystalline position in contact with protrusion 15 to control the concentration of polycrystalline material, thereby increasing the stability of the resistance when the polycrystalline material is energized with the metal, which helps to further enhance the control effect on Rg.
[0035] And, when the above structure is used to complete the accurate control of Rg, the process of manufacturing the MOSFET transistor is completed synchronously, that is, no process step is added, the control effect of Rg is increased on the existing production cost, the application range of the utility model is increased, the economic benefit is greatly increased, and the product quality is increased.
[0036] The preferred embodiments of the utility model are described above, and the protection scope of the utility model is not limited to the above-mentioned embodiments only, and any technical scheme belonging to the idea of the utility model belongs to the protection scope of the utility model. It should be pointed out that, for ordinary technical personnel in the technical field, some improvements and decorations without departing from the principle of the utility model are also regarded as the protection scope of the utility model.
Claims
1. A structure for adjusting built-in Rg of a trench gate MOSFET, comprising a silicon base substrate (17), an epitaxial layer (18) and an insulating layer (19) which are successively arranged from bottom to top in a vertical direction and integrated with a chip body, characterized in that: The epitaxial layer (18) and the insulating layer (19) are provided with a plurality of polycrystalline conducting channels (22) in communication with the gate on the chip body, and the plurality of polycrystalline conducting channels (22) are in communication through polycrystalline connecting channels (16), the insulating layer (19) is provided with a plurality of contact holes (20) in communication with the polycrystalline connecting channels (16), the insulating layer (19) is provided with a metal block (14), and the metal block (14) is provided with a protrusion (15) downwardly penetrating into the contact hole (20) and abutting against the polycrystalline connecting channel (16), and the metal block (14) is in electrical connection with the outside.
2. The structure for adjusting the built-in Rg of a trench gate MOSFET according to claim 1, characterized in that: Each of the contact holes (20) is a rectangular hole structure with equal size, and the protrusion (15) fills the contact hole (20).
3. The structure of adjusting built-in Rg of trench gate MOSFET according to claim 1, characterized in that: The position where the polycrystalline connecting channel (16) contacts the metal block (14) is provided with an SRC source layer (21), which is a polycrystalline structure for injecting N-type substance into the polycrystalline connecting channel (16).
4. The structure of adjusting built-in Rg of trench gate MOSFET according to claim 1, characterized in that: The SRC source layer (21) on the polycrystalline connecting channel (16) is located at the same layer as the source layer on the MOSFET transistor of the chip body.
5. The structure for adjusting built-in Rg of a trench gate MOSFET according to claim 1, characterized in that: The metal block (14) and the metal on the source of the MOSFET transistor of the chip body for electrically connecting the outside are located at the same horizontal plane.