CN214797437U

CN214797437U - PNP type phototransistor structure

Info

Publication number: CN214797437U
Application number: CN202120581581.8U
Authority: CN
Inventors: 伍建国
Original assignee: Shenzhen Deming New Microelectronics Co ltd
Current assignee: Shenzhen Deming New Microelectronics Co ltd
Priority date: 2021-03-22
Filing date: 2021-03-22
Publication date: 2021-11-19
Anticipated expiration: 2031-03-22

Abstract

The utility model provides a PNP type phototransistor structure, include: the first P-type region is externally wrapped on the N-type region, the N-type region is externally wrapped on the second P-type region, and the upper end surfaces of the first P-type region, the N-type region and the second P-type region form a contact surface positioned on the same plane; the photosensitive area is positioned on the upper layer of the contact surface; the lower end of the first P-type region is also provided with a substrate connected with a collector pin; the upper end surface of the second P-type area is provided with a first conductor, and the orthographic projection surface of the first conductor is smaller than that of the upper end surface of the second P-type area; and the upper end surface of the N-type area is provided with a second conductor, and the orthographic projection surface of the second conductor is smaller than that of the upper end surface of the N-type area. The conduction and the cut-off between the collector and the emitter of the photosensitive area can be controlled through the photosensitive area, the control can be carried out through the base pin, and the cooperative control of the photosensitive area and the base pin is realized; through the improvement on the structure, the conduction resistance of the transistor is further reduced, and during work, the loss and the heat generation on the transistor can be effectively reduced, the aging is delayed, and the service life is prolonged.

Description

PNP type phototransistor structure

Technical Field

The utility model relates to a phototransistor structural technical field especially relates to a PNP type phototransistor structure.

Background

With the development of electronic technology, a transistor is commonly used as a semiconductor device for an amplifier or an electrically controlled switch. Transistors are the basic building blocks that are the norm for operating computers, cell phones, and all other modern electronic circuits. Because of its fast response speed and high accuracy, the transistor can be used for various digital and analog functions including amplification, switching, voltage stabilization, signal modulation and oscillator. The transistors may be packaged individually or in a very small area, containing a portion of one hundred million or more transistor integrated circuits.

With the development of the photoelectric technology, phototransistors become important photosensitive elements applied to various photosensitive circuits, such as photoswitch circuits and the like, and bring great convenience to the life of people.

However, the base region of the existing phototransistor is only a photosensitive region and base region pins, when the phototransistor and a common triode are needed to be used in a circuit, a plurality of tubes need to be used and matched, the use is inconvenient, and the detection of the phototransistor needs to be in a light position or a specific detection occasion; and the existing photoelectric transistor structure has larger loss during operation due to larger internal resistance, and needs further improvement.

SUMMERY OF THE UTILITY MODEL

In view of the above, the present invention has been made in order to provide a PNP type phototransistor structure that overcomes or at least partially solves the above problems.

In order to solve the above problem, the utility model discloses a PNP type phototransistor structure, include:

a first P-type area, an N-type area, a second P-type area and a photosensitive area are sequentially arranged from the bottom end to the upper end, the first P-type area is wrapped outside the N-type area, the N-type area is wrapped outside the second P-type area, and the upper end surfaces of the first P-type area, the N-type area and the second P-type area form a contact surface located on the same plane;

the photosensitive area is positioned on the upper layer of the contact surface;

the lower end of the first P-type region is also provided with a substrate connected with a collector pin;

the upper end face of the second P-type area is provided with a first conductor which is connected with the pin of the emitter through the photosensitive area, and the orthographic projection surface of the first conductor is smaller than the upper end face of the second P-type area;

and the upper end surface of the N-type region is provided with a second conductor which is connected with the base pin through the photosensitive region, and the orthographic projection surface of the second conductor is smaller than the upper end surface of the N-type region.

Preferably, the first P-type region includes a first P-type low-concentration doped region and a first P + -type high-concentration doped region, wherein the first P + -type high-concentration doped region is connected to the substrate.

Preferably, the upper end surface of the N-type region is located in the central region of the upper end surface of the first P-type region.

Preferably, the upper end face of the second P-type region is located in the central area of the upper end face of the N-type region.

Preferably, the cross section of the second conductor is smaller than the cross section of the first conductor.

Preferably, the first conductor is welded with a first lead connected with the emitter pin, and the second conductor is welded with a second lead connected with the base pin.

Preferably, the photosensitive region is encapsulated in a transparent window.

Preferably, the second P-type region is a P + high concentration doped region.

Preferably, the N-type region is an N-type low-concentration doped region.

The utility model discloses a following advantage:

the utility model provides a phototransistor (photosensitive transistor) not only comprises a photosensitive area of a common photosensitive transistor, but also comprises a base pin of the common transistor; the conduction and the cut-off between the collector and the emitter of the photosensitive area can be controlled through the photosensitive area, the control can be carried out through the base pin, and the cooperative control of the photosensitive area and the base pin is realized; when the photoelectric transistor is detected, the detection can be realized only by a common instrument (such as a universal meter) without a specific illumination environment and special equipment;

through the improvement on the structure, the conduction resistance of the transistor is further reduced, and during work, the loss and the heat generation on the transistor can be effectively reduced, the aging is delayed, and the service life is prolonged.

Drawings

Fig. 1 is a cross-sectional view of a PNP phototransistor of the present invention;

fig. 2 is a top view of a PNP phototransistor structure according to the present invention;

fig. 3 is a structural view of a PNP type phototransistor in the related art.

The drawings illustrate the following:

1. a first P-type region; 2. an N-type region; 3. a second P-type region; 4. a light sensing area; 5. a substrate; 6. a first conductor; 7. a second conductor; 11. a first P-type low-concentration doped region; 12. a first P + type high concentration doped region.

Detailed Description

In order to make the above objects, features and advantages of the present invention more comprehensible, the present invention is described in detail with reference to the accompanying drawings and the embodiments.

One of the core ideas of the utility model is that a first P-type area, an N-type area, a second P-type area and a photosensitive area are sequentially arranged from the bottom end to the upper end, and the first P-type area is wrapped outside the N-type area and the N-type area is wrapped outside the second P-type area, so that the upper end surfaces of the first P-type area, the N-type area and the second P-type area form a contact surface on the same plane; the photosensitive area is positioned on the upper layer of the contact surface; the lower end of the first P-type region is also provided with a substrate connected with a collector pin; the upper end face of the second P-type area is provided with a first conductor which is connected with the pin of the emitter through the photosensitive area, and the orthographic projection surface of the first conductor is smaller than the upper end face of the second P-type area; and the upper end surface of the N-type region is provided with a second conductor which is connected with the base pin through the photosensitive region, and the orthographic projection surface of the second conductor is smaller than the upper end surface of the N-type region.

Referring to fig. 1-2, a PNP-type phototransistor structure of the present invention is shown, which may specifically include: a first P-type area 1, an N-type area 2, a second P-type area 3 and a light sensing area 4 are sequentially arranged from the bottom end to the upper end, the first P-type area 1 is wrapped outside the N-type area 2, the N-type area 2 is wrapped outside the second P-type area 3, and the upper end faces of the first P-type area 1, the N-type area 2 and the second P-type area 3 form a contact surface located on the same plane; the photosensitive area 4 is positioned on the upper layer of the contact surface; the lower end of the first P-type region 1 is also provided with a substrate 5 connected with a collector pin; a first conductor 6 connected with an emitter pin through a photosensitive area 4 is arranged on the upper end surface of the second P-type area 3, and the orthographic projection surface of the first conductor 6 is smaller than that of the upper end surface of the second P-type area 3; and the upper end surface of the N-type region 2 is provided with a second conductor 7 which is connected with a base pin through the photosensitive region 4, and the orthographic projection surface of the second conductor 7 is smaller than that of the upper end surface of the N-type region 2.

In the above embodiment, the PNP phototransistor includes not only the photosensitive region of the common phototransistor but also the base terminal of the common phototransistor; the conduction and the cut-off between the collector and the emitter of the photosensitive area can be controlled through the photosensitive area, the control can be carried out through the base pin, and the cooperative control of the photosensitive area and the base pin is realized; and the detection can be realized only by a common instrument (such as a multimeter) without specific illumination environment and special equipment when the phototransistor is detected.

It can be understood that, referring to fig. 3, a conventional photosensitive transistor structure in the prior art is shown, which does not have a base pin, and only can make its collector and emitter conductive by the photosensitive function of the photosensitive region.

In one embodiment, the first P-type region 1 includes a first P-type low-concentration doped region 11 and a first P + -type high-concentration doped region 12, wherein the first P + -type high-concentration doped region 12 is connected to the substrate 5.

In the above embodiment, the first P + type high concentration doped region 12 included in the first P-type region 1 has a lower resistivity due to its high doping concentration, so as to reduce the on-resistance of the transistor and improve the on-performance of the transistor, while the first P-type low concentration doped region enables the PN junction to have a higher avalanche voltage (i.e., breakdown voltage), so as to improve the voltage endurance of the transistor.

In one embodiment, the upper end surface of the N-type region 2 is located in the central region of the upper end surface of the first P-type region 1; the upper end surface of the second P-type region 3 is positioned in the central area of the upper end surface of the N-type region 2. Understandably, the PN junction between the base electrode and the emitter electrode of the transistor is positioned in the center of the N-type region 2, and the PN junction between the base electrode and the collector electrode of the transistor is positioned in the center of the first P-type region 1, so that the current distribution in the transistor is more uniform when the PN junction is conducted, and the condition of local heating of the transistor during operation is eliminated.

In an embodiment, the cross section of the second conductor 7 is smaller than the cross section of the first conductor 6; and a first lead connected with the pin of the emitter is welded on the first conductor 6, and a second lead connected with the pin of the base is welded on the second conductor 7.

In one embodiment, the photosensitive region 4 is encapsulated in a transparent window, for example, a transparent thin film, organic glass or transparent resin with high light transmittance can be used as the transparent window for encapsulating the transistor.

In one embodiment, the second P-type region 3 is a P + heavily doped region. Understandably, the second P-type region 3 connected to the emitter region is a P + high-concentration doped region, which has high doping concentration and lower resistivity, and further reduces the on-resistance of the transistor; because the collector and the emitter of the transistor have certain internal resistance after being conducted, after the current is passed, according to a heat power consumption formula, under the condition of certain current, the larger the internal resistance is, the larger the heat productivity is when the transistor works, and therefore, the transistor has the advantages of reducing the conduction resistance, reducing the power consumption of the transistor, reducing the heat productivity, delaying the aging time and prolonging the service life.

In one embodiment, the N-type region 2 is an N-type low-concentration doped region. Understandably, the PN junction formed by the P + region with high concentration further raises the avalanche voltage (i.e. breakdown voltage) of the PN junction of the transistor, thereby further enhancing the overall voltage endurance thereof.

Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or terminal that comprises the element.

The PNP-type phototransistor structure provided by the present invention is introduced in detail, and the principle and the implementation of the present invention are explained by using specific examples, and the descriptions of the above examples are only used to help understand the method and the core idea of the present invention; meanwhile, for the general technical personnel in the field, according to the idea of the present invention, there are changes in the specific implementation and application scope, to sum up, the content of the present specification should not be understood as the limitation of the present invention.

Claims

1. A PNP type phototransistor structure, comprising:

2. The PNP type phototransistor structure of claim 1, wherein the first P type region comprises a first P type low concentration doped region and a first P + type high concentration doped region, and wherein the first P + type high concentration doped region is connected to the substrate.

3. The PNP phototransistor structure of claim 1, wherein the top surface of the N-type region is located in a central region of the top surface of the first P-type region.

4. The PNP type phototransistor structure of claim 1, wherein the upper end surface of the second P type region is located at a central region of the upper end surface of the N type region.

5. The PNP-type phototransistor structure of claim 1, wherein the cross section of the second conductor is smaller than the cross section of the first conductor.

6. The PNP phototransistor structure of claim 1 or 5, wherein the first conductor bond has a first wire connected to the emitter pin and the second conductor bond has a second wire connected to the base pin.

7. The PNP phototransistor structure of claim 1, wherein the photosensitive region is encapsulated within a transparent window.

8. The PNP type phototransistor structure of claim 1, wherein the second P type region is a P + heavily doped region.

9. The PNP phototransistor structure of claim 1, wherein the N-type region is an N-type low concentration doped region.