Transistor structure for improving current capability and manufacturing method
By setting up a hollow ring structure on the transmitting area of the high-frequency transistor and setting up an ohmic hole in the interlaced manner, the problem of low current capability of the high-frequency transistor is solved, and a significant improvement in current capability and comprehensive improvement in performance is achieved.
Patent Information
- Application Number
- CN202411771785.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-04
- Publication Date
- 2025-04-08
AI Technical Summary
The current capacity of existing high-frequency transistors is small and difficult to apply to areas with high current requirements.
By providing a hollow ring-shaped structure on the emission region of the transistor, and interlaced with base ohmic holes and emitter ohmic holes without changing the chip area, the side length and contact area of the emission region are increased.
It significantly improves the current transmission capability of the transistor, enhances the smoothness of current flow, reduces resistance and capacitance effects, and improves heat dissipation performance.
Smart Images
Figure CN119789473A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of chip manufacturing process, and in particular to a transistor structure and a manufacturing method for improving current capability. Background Art
[0002] With the development of various power electronic systems towards miniaturization, intelligence and automation, the operating frequency of electronic systems is getting higher and higher. Therefore, there are higher requirements for the performance of transistors, especially the requirements for the operating frequency of transistors. High-frequency transistors are widely used in some high-frequency and high-reliability equipment.
[0003] Due to its high frequency characteristics, high-frequency transistors are limited by their frequency characteristics. The active area of conventional high-frequency transistors adopts a small area and narrow electrode design structure, that is, the active area size of high-frequency transistors is usually very small, so as to increase the frequency of the transistor. However, the current capacity of the transistor is determined by the effective side length of the emitter area. The small active area design of high-frequency transistors means that the side length of its emitter area is usually very small, which leads to the current capacity of conventional high-frequency transistors being very small. At present, the process structure of mainstream high-frequency transistors uses conventional structure design. High-frequency transistors have the disadvantage of small current capacity and are difficult to be used in some fields with high current requirements. Summary of the invention
[0004] In order to overcome the defects of the prior art, the present invention aims to provide a transistor structure and a manufacturing method for improving the current capability, so as to solve the technical problem of how to improve the current capability of the transistor in the prior art.
[0005] The present invention is achieved through the following technical solutions: In a first aspect, the present invention provides a transistor structure for improving current capability, comprising a transistor body, an emitter, and a base; The transistor body is provided with a plurality of base ohmic holes and emitter ohmic holes in parallel in sequence along the long side direction; the plurality of base ohmic holes and emitter ohmic holes are arranged alternately; The emitter and the base are respectively arranged on both sides of the transistor body, wherein the emitter is provided with a plurality of emitter lead-out terminals, and the base is provided with a plurality of base lead-out terminals; A plurality of emitter lead-out terminals are respectively and correspondingly arranged on a plurality of emitter ohmic holes, and a plurality of base lead-out terminals are respectively and correspondingly arranged on a plurality of base ohmic holes.
[0006] Preferably, the transistor body comprises a base region and an emitter region; The emitter region is arranged on the base region, wherein both the base region and the emitter region are rectangular structures; A plurality of rectangular holes are arranged in parallel along the long side of the emitting area to form a hollow structure; A plurality of base ohmic holes are correspondingly arranged in a plurality of rectangular holes; a plurality of emitter ohmic holes are correspondingly arranged in the area between the plurality of adjacent rectangular holes.
[0007] Furthermore, the rectangular area of the base region is larger than the rectangular area of the emitter region.
[0008] Furthermore, the hole surface area of the rectangular hole is larger than the hole surface area of the base ohmic hole.
[0009] Furthermore, the area of the region between the adjacent rectangular holes is larger than the hole surface area of the emitter ohmic hole.
[0010] Furthermore, the width of the rectangular hole is smaller than the width of the emission area, and the length of the rectangular hole is smaller than the length of the emission area.
[0011] Furthermore, the thickness of the base region is 1.5 μm to 2 μm, and the thickness of the emitter region is 0.5 μm to 1.0 μm.
[0012] Furthermore, a collector is provided at the bottom of the base region.
[0013] In a second aspect, the present invention further provides a method for manufacturing a transistor structure for improving current capability, based on the above-mentioned transistor structure for improving current capability, comprising the following process: Photolithography is performed on a silicon wafer to form a base region, and photolithography is performed on the base region to form an emitter region; Through the photolithography hole process, base ohmic holes and emitter ohmic holes are formed in the base area and emitter area respectively. Then metal is deposited on the front side. Then, through the photolithography of metal and alloy, ohmic contact is formed between the metal and the base ohmic hole and the emitter ohmic hole, thereby forming the base and emitter of the transistor respectively. Finally, metallization is performed on the back of the silicon wafer, and the back of the chip is the collector of the transistor.
[0014] Preferably, a plurality of rectangular holes are photoetched on the emitter region, and the plurality of rectangular holes form a hollow structure in the emitter region.
[0015] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention provides a transistor structure for improving current capacity, wherein a transistor body is provided with a plurality of base ohmic holes and emitter ohmic holes in parallel in sequence along the long side direction; the plurality of base ohmic holes and emitter ohmic holes are arranged alternately; the emitter and the base are arranged on both sides of the transistor body, wherein the emitter is provided with a plurality of emitter lead-out terminals, and the base is provided with a plurality of base lead-out terminals; the plurality of emitter lead-out terminals are respectively arranged on the plurality of emitter ohmic holes, and the plurality of base lead-out terminals are respectively arranged on the plurality of base ohmic holes, wherein without changing the chip area of the high-frequency transistor, only the emitter region structure is modified and optimized, and the emitter region strip structure of the conventional high-frequency transistor is changed into a hollow ring structure; the current capacity of the transistor is increased by increasing the side length of the emitter region.
[0016] Furthermore, by changing the strip structure of the emitter region of a conventional high-frequency transistor into a hollow ring structure, and without changing the area of the transistor chip, the side length of the emitter region is effectively increased, and the contact area between the emitter region and the base region is increased, thereby improving the current transmission capacity of the transistor.
[0017] Furthermore, the staggered arrangement of the base ohmic holes and the emitter ohmic holes, and their corresponding arrangement with the emitter and base lead terminals, ensures a smooth flow of current, helps to reduce resistance and capacitance effects, and further improves the current performance of the transistor.
[0018] Furthermore, the transistor structure of the present invention achieves an improvement in current capability by optimizing the emitter structure and the layout of the ohmic hole without increasing the chip area, which improves the utilization of the chip area and enables higher performance to be obtained at the same chip size.
[0019] Furthermore, the hollow ring-shaped emitter area helps improve the heat dissipation performance of the transistor. Compared with the traditional strip structure, the ring structure provides more heat dissipation channels, which helps to transfer heat from the inside of the transistor to the external environment more effectively.
[0020] The present invention also provides a method for manufacturing a transistor structure for improving current capacity, based on existing semiconductor manufacturing processes such as photolithography, metal deposition and alloying, without the need to introduce new equipment or materials. This makes the method easy to implement on existing production lines and reduces production costs. Through precise photolithography and metallization processes, silicon wafer materials and metal materials can be utilized to the maximum extent, reducing waste. This helps to improve production efficiency and reduce manufacturing costs. The specific shape, size and number of the hollow structure can be adjusted as needed to adapt to different application scenarios and performance requirements. This design flexibility enables transistors to better meet various needs. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 A schematic diagram of a transistor structure in an embodiment of the present invention; Figure 2 Schematic diagram of the structure of the base region and the emitter region in an embodiment of the present invention, wherein Figure a is a schematic diagram of the base region; Figure b is a schematic diagram of the emitter region; In the figure: 1. transistor body; 2. emitter; 3. base; 11. base region; 12. emitter region; 13. base ohmic hole; 14. emitter ohmic hole. DETAILED DESCRIPTION
[0022] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.
[0023] The object of the present invention is to provide a transistor structure and a manufacturing method for improving the current capability, so as to solve the technical problem of how to improve the current capability of the transistor in the prior art.
[0024] The present invention is further described in detail below in conjunction with the accompanying drawings: Example 1 See also Figure 1 In one embodiment of the present invention, a transistor structure for improving current capability is provided, comprising a transistor body 1, an emitter 2 and a base 3; The transistor body 1 is provided with a plurality of base ohmic holes 13 and emitter ohmic holes 14 in parallel in sequence along the long side direction; the plurality of base ohmic holes 13 and emitter ohmic holes 14 are arranged alternately; The emitter 2 and the base 3 are respectively arranged on both sides of the transistor body 1, wherein the emitter 2 is provided with a plurality of emitter lead-out terminals, and the base 3 is provided with a plurality of base lead-out terminals; The plurality of emitter lead-out terminals are respectively arranged on the plurality of emitter ohmic holes 14 , and the plurality of base lead-out terminals are respectively arranged on the plurality of base ohmic holes 13 .
[0025] Specifically, according to Figure 2 As shown, the transistor body 1 includes a base region 11 and an emitter region 12, wherein Figure 2 The middle figure a is the base region 11, and the middle figure b is the emitter region 12.
[0026] The emitter region 12 is disposed on the base region 11, wherein the base region 11 and the emitter region 12 are both rectangular structures; The emitting area 12 is provided with a plurality of rectangular holes arranged in parallel along the long side direction to form a hollow structure; A plurality of base ohmic holes 13 are correspondingly arranged in a plurality of rectangular holes; a plurality of emitter ohmic holes 14 are correspondingly arranged in the area between the plurality of adjacent rectangular holes.
[0027] Among them, the rectangular area of the base region 11 is larger than the rectangular area of the emitter region 12; the hole surface area of the rectangular hole is larger than the hole surface area of the base ohmic hole 13; the area of the region between several adjacent rectangular holes is larger than the hole surface area of the emitter ohmic hole 14; the width of the rectangular hole is smaller than the width of the emitter region 12, and the length of the rectangular hole is smaller than the length of the emitter region 12; the thickness of the base region 11 is 1.5μm~2μm, and the thickness of the emitter region 12 is 0.5μm~1.0μm; a collector is provided at the bottom of the base region 11.
[0028] In this embodiment, a rectangular hole is provided on the emitter region to form a hollow structure, which effectively increases the equivalent perimeter (or side length) of the emitter region. This increases the contact area between the emitter region and the base region, allowing more current to pass through the transistor. The hollow structure changes the flow path of the current in the emitter region, allowing the current to be more evenly distributed on the emitter region, reducing the current crowding effect, thereby improving the current transmission efficiency.
[0029] The base ohmic hole and the emitter ohmic hole are respectively arranged in the rectangular hole and in the area between the adjacent rectangular holes. This configuration ensures that the current can smoothly pass from the emitter to the base through the emitter area, while reducing the resistance and capacitance effects.
[0030] Through metal deposition and alloying processes, the metal forms a reliable ohmic contact with the ohmic hole, which reduces the contact resistance and improves the current transmission efficiency.
[0031] When an external voltage is applied to the emitter and base of the transistor, the electrons in the emitter are accelerated and injected into the emitter region. Since the emitter region adopts a hollow structure, the electrons can be more evenly distributed in the emitter region and more easily cross to the base region.
[0032] In the base region, electrons and holes recombine to release energy. At the same time, the configuration of the base ohmhole and emitter ohmhole ensures that current can smoothly pass through the transistor and be output to the collector.
[0033] This embodiment can significantly improve the current capacity of high-frequency transistors at a very small cost while keeping the chip area unchanged. From semiconductor theory, it can be known that the current capacity of a transistor is mainly determined by the side length of the emitter region. The empirical value of the relationship between the unit side length of the emitter region and the current is 0.04~0.16mA / μm (this value is mainly determined by the process of each wafer production line). The larger the side length of the emitter region, the greater the current capacity of the transistor. The present invention mainly increases the current capacity of the transistor by increasing the side length of the emitter region.
[0034] Among them, without changing the chip area of the high-frequency transistor, only the emitter region structure is modified and optimized, and the emitter region strip structure of the conventional high-frequency transistor is changed to a hollow ring structure; compared with the layout design structure of the conventional high-frequency transistor, the present invention only modifies and optimizes the emitter region structure design, and the other layout layer design structures are not changed, thereby achieving a significant improvement in current capacity at a minimum cost; In this embodiment, since the transistor current capacity is mainly determined by the side length of the emitter region, by adopting the optimized new high-frequency transistor design structure, the side length of the emitter region can be significantly increased compared with the conventional structure by only optimizing and changing the emitter region design structure without changing the chip area, thereby significantly improving the chip current capacity on the original basis and significantly improving the electrical performance of the chip.
[0035] In summary, the present embodiment provides a transistor structure for improving the current capability, by providing a plurality of base ohmic holes and emitter ohmic holes in parallel in sequence along the long side direction of the transistor body; the plurality of base ohmic holes and emitter ohmic holes are arranged alternately; the emitter and the base are respectively arranged on both sides of the transistor body, wherein the emitter is provided with a plurality of emitter lead-out terminals, and the base is provided with a plurality of base lead-out terminals; the plurality of emitter lead-out terminals are respectively arranged on the plurality of emitter ohmic holes, and the plurality of base lead-out terminals are respectively arranged on the plurality of base ohmic holes, wherein without changing the chip area of the high-frequency transistor, only the emitter region structure is changed and optimized, and the emitter region strip structure of the conventional high-frequency transistor is changed into a hollow ring structure; the current capability of the transistor is increased by increasing the side length of the emitter region.
[0036] Example 2 This embodiment 2 provides a method for manufacturing a transistor structure for improving current capability, based on the above-mentioned transistor structure for improving current capability, including the following process: A base region 11 is photolithographically formed on a silicon wafer, and an emitter region 12 is photolithographically formed on the base region 11; A base ohmic hole 13 and an emitter ohmic hole 14 are formed in the base 11 region and the emitter 12 region respectively through a photolithography hole process, and then metal is deposited on the front side, and then the metal and alloy are photolithographically formed to form ohmic contact with the base ohmic hole 13 and the emitter ohmic hole 14, thereby forming the base 3 and the emitter 2 of the transistor respectively; finally, metallization is performed on the back side of the silicon wafer, and the back side of the chip is the collector of the transistor.
[0037] Specifically, a plurality of rectangular holes are photoetched on the emitter 12 region, and the plurality of rectangular holes form a hollow structure in the emitter 12 region.
[0038] In this embodiment, the base region 11 and the emitter region 12 are first accurately calibrated on the silicon wafer by photolithography. By photolithography hole process, base ohmic holes 13 and emitter ohmic holes 14 are formed in the base region 11 and the emitter region 12, respectively. A layer of metal is deposited on the front of the silicon wafer, and then photolithography and alloying are performed to form a good ohmic contact between the metal and the base ohmic hole 13 and the emitter ohmic hole 14. Metallization is performed on the back of the silicon wafer to form the collector of the transistor. Back metallization is usually performed by evaporation or sputtering to form a good ohmic contact and provide a stable current path.
[0039] In this embodiment, when no current passes through the transistor, due to the low doping concentration of the base region, there are few electrons and holes, so the free electrons in the emitter region cannot reach the collector region through the base region. At this time, the transistor is in a cut-off state. When a forward bias voltage is applied to the base region, free electrons begin to flow from the emitter region into the base region and recombine with the holes in the base region. This process will increase the number of electrons in the base region, thereby reducing the electron concentration gradient in the base region. When the electron concentration in the base region drops below a critical value, electrons begin to conduct through the base region to the collector region. At this time, the transistor is in an amplification state, and current flows from the emitter region to the collector region. By adjusting the voltage between the base and the emitter, the amplification factor of the transistor can be controlled. When both the emitter junction and the collector junction are forward biased, the transistor operates in a saturation region. At this time, the current from the emitter to the collector of the transistor reaches a maximum value, and even if the base current is increased, the output current will not increase.
[0040] This embodiment takes an NPN transistor as an example, and the specific process is as follows: First, the base region is photolithographically formed on the N+ substrate and N- epitaxial silicon wafer, and then a P-type base region is formed by boron implantation and boron annealing. The expansion depth of the base region is 1.5μm to 2μm.
[0041] Then, the emitter region is photolithographically formed in the base region (the coverage of the base region on the emitter region is 4 μm), and an N+ emitter region is formed by phosphorus injection and phosphorus annealing. The expansion depth of the N+ emitter region is 0.5 μm to 1.0 μm.
[0042] The base ohmic hole and emitter ohmic hole are formed in the base area and emitter area respectively through the photolithography hole process, and then metal is deposited on the front side, and then the metal and the base ohmic hole and the emitter ohmic hole are formed into ohmic contact by photolithography metal and alloy, thereby forming the base and emitter of the NPN transistor respectively. Finally, metallization is performed on the back of the silicon wafer, and the back of the chip is the collector of the high-frequency NPN transistor.
[0043] The present embodiment is applied to the actual high-frequency NPN transistor chip manufacturing, and the design and structure verification are carried out through the actual product tape-out, and then the tape-out is carried out on the semiconductor chip production line; two schemes are used for comparative tape-out, scheme one is a conventional high-frequency NPN transistor structure, and scheme two is the transistor structure of the present embodiment; After comparative testing of the two qualified structure chips, the chip obtained by using the transistor structure design of this embodiment has an emitter area side length increased by about 50% compared with the chip of the conventional high-frequency NPN transistor structure of solution 1, and the current capacity of the chip is also improved by about 50%. Without changing the chip area, only by changing the emitter area structure, the performance of the chip is significantly improved at the minimum cost. The comparison test results of the chip current capacity of the two solutions are shown in Table 1.
[0044] Table 1 Comparison test results of high-frequency NPN transistor current capabilities of two solutions
[0045] After comparative testing of high-frequency NPN transistors with two different structures, the transistor using this embodiment has significantly improved current capability compared to the NPN transistor using the conventional structure of Scheme 1. Compared with the high-frequency NPN transistor of Scheme 1, this embodiment significantly improves the current capability of the NPN transistor at the lowest cost by only changing the optimized emitter structure design without changing the chip area, which has a good reference significance for the design of other high-frequency tubes and conventional transistors.
[0046] In summary, the present invention changes the strip structure of the emitter region of a conventional high-frequency transistor into a hollow ring structure, and effectively increases the side length of the emitter region without changing the chip area of the transistor, and increases the contact area between the emitter region and the base region, thereby improving the current transmission capacity of the transistor. The staggered arrangement of the base ohmic holes and the emitter ohmic holes, as well as their corresponding arrangement with the emitter and base lead terminals, ensure the smooth flow of current, help reduce the resistance and capacitance effects, and further improve the current performance of the transistor. The transistor structure of the present invention achieves an improvement in current capacity by optimizing the layout of the emitter region structure and the ohmic holes without increasing the chip area. This improves the utilization rate of the chip area, so that higher performance can be obtained at the same chip size. The emitter region of the hollow ring structure helps to improve the heat dissipation performance of the transistor. Compared with the traditional strip structure, the ring structure provides more heat dissipation channels, which helps to transfer heat more effectively from the inside of the transistor to the external environment.
[0047] The present invention is based on existing semiconductor manufacturing processes such as photolithography, metal deposition and alloying during the manufacturing process, and no new equipment or materials need to be introduced. This makes the method easy to implement on existing production lines and reduces production costs. Through precise photolithography and metallization processes, silicon wafer materials and metal materials can be utilized to the maximum extent, reducing waste. This helps to improve production efficiency and reduce manufacturing costs. The specific shape, size and number of the hollow structure can be adjusted as needed to adapt to different application scenarios and performance requirements. This design flexibility enables transistors to better meet various needs.
[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.
Claims
1. A transistor structure for improving current capability, characterized in that: It comprises a transistor body (1), an emitter (2) and a base (3); The transistor body (1) is provided with a plurality of base ohmic holes (13) and emitter ohmic holes (14) arranged in parallel in sequence along the long side direction; the plurality of base ohmic holes (13) and emitter ohmic holes (14) are arranged in an alternating manner; The emitter (2) and the base (3) are respectively arranged on two sides of the transistor body (1), wherein the emitter (2) is provided with a plurality of emitter lead-out terminals, and the base (3) is provided with a plurality of base lead-out terminals; The plurality of emitter lead-out terminals are respectively and correspondingly arranged on the plurality of emitter ohmic holes (14), and the plurality of base lead-out terminals are respectively and correspondingly arranged on the plurality of base ohmic holes (13).
2. A transistor structure for improving current capability according to claim 1, characterized in that: The transistor body (1) comprises a base region (11) and an emitter region (12); The emitter region (12) is arranged on the base region (11), wherein the base region (11) and the emitter region (12) both have a rectangular structure; A plurality of rectangular holes are arranged in sequence along the long side direction on the emitting area (12) to form a hollow structure; A plurality of base ohmic holes (13) are correspondingly arranged in a plurality of rectangular holes; and a plurality of emitter ohmic holes (14) are correspondingly arranged in the area between adjacent rectangular holes.
3. A transistor structure for improving current capability according to claim 2, characterized in that: The rectangular area of the base region (11) is larger than the rectangular area of the emission region (12).
4. A transistor structure for improving current capability according to claim 2, characterized in that: The hole surface area of the rectangular hole is greater than the hole surface area of the base ohmic hole (13).
5. The transistor structure for improving current capability according to claim 2, characterized in that: The area of the region between the adjacent rectangular holes is greater than the hole surface area of the emitter ohmic hole (14).
6. The transistor structure for improving current capability according to claim 2, characterized in that: The width of the rectangular hole is smaller than the width of the emission area (12), and the length of the rectangular hole is smaller than the length of the emission area (12).
7. A transistor structure for improving current capability according to claim 2, characterized in that: The thickness of the base region (11) is 1.5 μm to 2 μm, and the thickness of the emission region (12) is 0.5 μm to 1.0 μm.
8. The transistor structure for improving current capability according to claim 2, characterized in that: A collector is provided at the bottom of the base region (11).
9. A method for manufacturing a transistor structure for improving current capability, characterized in that: A transistor structure for improving current capability according to any one of claims 1 to 8, comprising the following process: Photolithography is performed on a silicon wafer to form a base region (11), and photolithography is performed on the base region (11) to form an emitter region (12); A base ohmic hole (13) and an emitter ohmic hole (14) are formed in the base (11) region and the emitter (12) region respectively by a photolithography hole process, and then metal is deposited on the front side, and then the metal and the alloy are photolithography-etched to form an ohmic contact with the base ohmic hole (13) and the emitter ohmic hole (14), thereby forming the base (3) and the emitter (2) of the transistor respectively; finally, metallization is performed on the back side of the silicon wafer, and the back side of the chip is the collector of the transistor.
10. The method for manufacturing a transistor structure for improving current capability according to claim 9, characterized in that: A plurality of rectangular holes are photoetched on the emitter (12) region, and the plurality of rectangular holes form a hollow structure in the emitter (12) region.