TW201438108A - Bipolar junction transistor and operating and manufacturing method for the same - Google Patents

Abstract

A bipolar junction transistor and an operating method and a manufacturing method for the same are provided. The bipolar junction transistor comprises a first doped region, a second doped region and a third doped region. The first doped region has a first type conductivity. The second doped region comprises well regions formed in the first doped region, having a second type conductivity opposite to the first type conductivity, and separated from each other by the first doped region. The third doped region has the first type conductivity. The third doped region is formed in the well regions or in the first doped region between the well regions.

Description

Bipolar junction transistor, operation method and manufacturing method thereof

The present disclosure relates to a semiconductor device, a method of operating the same, and a method of fabricating the same, and more particularly to a bipolar junction transistor, an operating method thereof, and a method of fabricating the same.

A semiconductor bipolar junction transistor (BJT) device can operate in a forward-active mode by controlling the voltage applied to the base and collector terminals. For example, the NPN-type bipolar junction transistor device has a P-type base region and an N-type collector region and an emitter region. During operation, a positive voltage V BE and a ratio V can be applied to the base terminal and the collector terminal, respectively. BE Higher positive voltage V CE. The emitter-base junction can thus be forward biased, the base-collector junction can thus be reverse biased, and the base current IB and collector current IC can be reduced. The collector current IC is defined as the base. The current of the pole current IB is β times. Therefore, the bipolar junction transistor device can be used as a current amplifier with current gain or beta gain β.

Embodiments are related to bipolar junction transistors and methods of operation and methods of manufacture thereof that have good device characteristics.

According to an embodiment, a bipolar junction transistor is provided, including a first doped region, a second doped region, and a third doped region. The first doped region has a first conductivity type. The second doped region includes a plurality of well regions formed in the first doped region. The well region has a second conductivity type opposite to the first conductivity type. The well regions are separated from one another by a first doped region. The third doped region has a first conductivity type. The third doped region is formed in the well region or formed in the first doped region between the well regions.

According to an embodiment, a method of operating a bipolar junction transistor is provided. The bipolar junction transistor includes a first doped region, a second doped region, and a third doped region. The first doped region has a first conductivity type. The second doped region includes a plurality of well regions formed in the first doped region. The well region has a second conductivity type opposite to the first conductivity type. The well regions are separated from one another by a first doped region. The third doped region has a first conductivity type. The third doped region is formed in the well region or formed in the first doped region between the well regions. The method of operation includes the following steps. A collector voltage is provided to the first doped region. A base voltage is provided to the second doped region. An emitter voltage is provided to the third doped region.

According to an embodiment, a method of fabricating a bipolar junction transistor is provided, comprising the following steps. A plurality of well regions of a second doped region are formed in a first doped region. The first doped region has a first conductivity type. The well region has a second conductivity type opposite to the first conductivity type. The well regions are separated from one another by a first doped region. A third doped region is formed in the well region or in the first doped region between the well regions. The third doped region has a first conductivity type.

In order to better understand the above and other aspects of the present invention, the preferred embodiments are described below, and in conjunction with the drawings, the detailed description is as follows:

FIG. 1A is a top view of a bipolar junction transistor in accordance with an embodiment.
Fig. 1B is a cross-sectional view of the bipolar junction transistor of Fig. 1A taken along line BB.
Figure 1C is a cross-sectional view of the bipolar junction transistor of Figure 1A taken along line CC.
2A is a top view of a bipolar junction transistor in accordance with an embodiment.
Figure 2B is a cross-sectional view of the bipolar junction transistor of Figure 2A taken along line BB.
Figure 2C is a cross-sectional view of the bipolar junction transistor of Figure 2A taken along line CC.
3A is a top view of a bipolar junction transistor in accordance with an embodiment.
Figure 3B is a cross-sectional view of the bipolar junction transistor of Figure 3A taken along line BB.
Figure 3C is a cross-sectional view of the bipolar junction transistor of Figure 3A taken along line CC.
4A is a top view of a bipolar junction transistor in accordance with an embodiment.
Figure 4B is a cross-sectional view of the bipolar junction transistor of Figure 4A taken along line BB.
Figure 4C is a cross-sectional view of the bipolar junction transistor of Figure 4A taken along line CC.
FIG. 5A is a top view of a bipolar junction transistor in accordance with an embodiment.
Figure 5B is a cross-sectional view of the bipolar junction transistor of Figure 5A taken along line BB.
Figure 5C is a cross-sectional view of the bipolar junction transistor of Figure 5A taken along line CC.
6A is a cross-sectional view of a bipolar junction transistor in accordance with an embodiment.
6B is a cross-sectional view of a bipolar junction transistor in accordance with an embodiment.
Figure 7 is an electrical diagram of a bipolar junction transistor in accordance with an embodiment.
Figure 8 is an electrical diagram of a bipolar junction transistor in accordance with an embodiment.

FIG. 1A is a top view of a bipolar junction transistor in accordance with an embodiment. Figure 1B is a cross-sectional view of the bipolar junction transistor along line BB. Figure 1C is a cross-sectional view of the bipolar junction transistor along line CC.

Referring to FIG. 1B, the first doped region 102 includes a well region 104 and a contact region 106. The well region 104 and the contact region 106 have a first conductivity type such as an N conductivity type. The well zone 104 is on the substrate 108. The substrate 108 has a second conductivity type, such as a P conductivity type, opposite to the first conductivity type. In one embodiment, the well region 104 can be formed by doping the substrate 108. In other embodiments, well region 104 may be formed on substrate 108 in a manner that is grown or deposited. Well zone 104 can be a high pressure (HV) well zone. Well region 104 and substrate 108 may comprise a semiconductor material such as germanium, or other suitable material. Substrate 108 may include an insulating layer overlying germanium (SOI). Contact region 106 can be formed in a manner that is doped with well region 104. In an embodiment, contact region 106 is heavily doped.

Referring to FIG. 1B, the second doped region 110 includes a plurality of well regions 112, 114, 116. The well regions 112, 114, 116 have a second conductivity type, such as a P conductivity type. The well regions 112, 114, 116 may be formed by doping the well region 104 of the first doped region 102. The well regions 112, 114, 116 can be formed in an epitaxial manner. The well regions 112, 114, 116 of the second doped region 110 may be separated from one another by the well region 104 of the first doped region 102. The second doped region 110 includes a contact region 118 having a second conductivity type such as a P conductivity type. Contact region 118 may be formed in a manner that is doped with well region 112 and may be heavily doped.

Referring to FIG. 1B , the third doping region 120 includes a contact region 122 . The contact region 122 has a first conductivity type such as an N conductivity type. The method of forming the contact region 122 can include doping the well regions 114, 116 of the second doped region 110 and doping the well region 104 of the first doped region 102 between the well region 114 and the well region 116. Contact region 122 can be heavily doped.

Referring to FIG. 1B, a first top doped layer 124 having a second conductivity type is located on the well region 104 having the first doped region 102 of the first conductivity type. The first top doped layer 124 can be formed by doping the well region 104. A second top doped layer 126 having a first conductivity type is located on the first top doped layer 124. The second top doped layer 126 can be formed by doping the first top doped layer 124. A dielectric structure 128 is formed on the second top doped layer 126. The dielectric structure 128 is not limited to the field oxides as shown in FIGS. 1B and 1C, but may include other suitable dielectric structures such as shallow trench isolation and the like. Conductive structure 130 is formed on dielectric structure 128. In one embodiment, the conductive structure 130 includes polysilicon, for example, formed by a single poly or double poly process.

The difference in cross-sectional view of the bipolar junction transistor shown in FIG. 1C and FIG. 1B is that the first top doping layer 124 and the second top doping layer 126 in FIG. 1B are omitted in FIG. 1C. 1A is a top view of only a portion of a bipolar junction transistor, including a contact region 106 of the first doped region 102; a well region 112, 114, 116 and a contact region 118 of the second doped region 110; a contact region 122 of the three doped region 120; and a second top doped layer 126. The bipolar junction transistor is not limited to the circular configuration as in FIG. 1A, but can also be designed as a square, a rectangle, a hexagonal, an octagonal, or an octagonal. Or other shape structure.

2A to 2C are schematic views showing the bipolar junction transistors of FIGS. 1A to 1C, respectively, after the well regions 112, 114, 116 of the second doping region 110 are diffused. The step of diffusing the well regions 112, 114, 116 is to form the connection region 132 of the second doped region 110. The connection region 132 located below the contact region 122 of the third doping region 120 is adjacent between the well region 114 and the well region 116 and has a second conductivity type. The bottom surface of the well regions 114, 116 is lower than the bottom surface of the connection region 132. The method of diffusing the well regions 112, 114, 116 of the second doped region 110 can include performing an annealing step. This annealing step can be performed at any suitable timing, for example, before or after forming the contact region 118 of the second doping region 110 and the contact region 122 forming the third doping region 120.

Referring to FIG. 2B , in an embodiment, for example, the first doping region 102 of the bipolar junction transistor can be electrically connected to the collector voltage 134 by the contact region 106 . The second doped region 110 can be electrically connected to the base voltage 136 by the contact region 118. The third doped region 120 can be electrically connected to the emitter voltage 138 by the contact region 122. In other words, the first doped region 102 (including the first conductivity type, such as the N-conducting well region 104 and the contact region 106) is used as a collector. The second doped region 110 (including the second conductivity type, such as the P conductivity type well regions 112, 114, 116, the connection region 132, and the contact region 118) is used as a base. The third doping region 120 (including the first conductive type such as the N conductive type contact region 122) is used as an emitter. The conductive structure 130 can be electrically connected to the structure voltage. In one embodiment, the structure voltage is coupled to the base voltage 136.

Referring to FIG. 2B, in the embodiment, the well regions 112, 114, 116 after diffusion and the formed connection region 132 have a smaller doping concentration than the well regions 112, 114, 116 before diffusion, thereby improving the double The beta gain of the polar junction transistor. The formed connection region 132 can have a small size (e.g., shallow depth or narrow width) which can increase the base resistance and increase the beta gain. Thus, in other words, embodiments may be by adjusting the well regions 112, 114, 116 of the second doped region 110 (eg, the spacing between the well regions 112, 114, 116), or adjusting the diffusion well regions 112, 114, A process parameter of 116 (e.g., annealing) is used to control the formed junction region 132 to control the beta gain of the bipolar junction transistor.

Furthermore, the first top doped layer 124 and the second top doped layer 126 formed in the well region 104 (drift region) below the dielectric structure 128 are the concept of applying a reduced surface field (RESURF). It can help increase the breakdown voltage of high voltage bipolar junction transistors (HVBJT). The conductive structure 130 disposed on the dielectric structure 128 between the (collector) contact region 106 and the (base) contact region 118 can help to increase the junction breakdown voltage of the bipolar junction transistor. In one embodiment, the high voltage bipolar junction transistor can reduce the size of the device and reduce the operating voltage by reducing the size of the drift region (in the well region 104). In an embodiment, the distance between the (emitter) contact region 122 and the (collector) contact region 106 can be optimized to avoid lateral punch through of the bipolar junction transistor. Applied to high pressure devices.

In an embodiment, the bipolar junction transistor can be formed using a standard high voltage process, thus eliminating the need for additional processes, masks, or changing process recipes.

3A is a top view of a bipolar junction transistor in accordance with an embodiment. Figure 3B is a cross-sectional view of the bipolar junction transistor along line BB. Figure 3C is a cross-sectional view of the bipolar junction transistor along line CC.

The difference between the bipolar junction transistors of FIGS. 3A to 3B and the bipolar junction transistors of FIGS. 1A to 1B is that the contact regions 222A, 222B of the third doping region 220 are formed in the second Doped region 110 is in well region 114, 116. The difference between the 3B and 3C cross-sectional views is that the 3C diagram omits the contact regions 222A, 222B of the well regions 114, 116 and the third doping region 220 of the second doped region 110. The contact regions 222A, 222B of the well regions 114, 116 and the third doping region 220 of the second doping region 110 are not limited to the rectangular configuration as shown in FIG. 3A, but can also be designed as squares, six. A structure of hexagonal, octagonal, circular, or other shape.

4A to 4C are diagrams respectively showing the bipolar junction transistors of FIGS. 3A to 3C in an embodiment, after the well regions 112, 114, 116 of the second doping region 110 are diffused. . The step of diffusing the well regions 112, 114, 116 is to form the connection region 132 of the second doped region 110. The connection region 132 is adjacent between the well regions 112, 114, 116 and has a second conductivity type. The bottom surface of the well regions 112, 114, 116 is lower than the bottom surface of the connection region 132. The method of diffusing the well regions 112, 114, 116 of the second doped region 110 can include performing an annealing step. This annealing step can be performed at any suitable timing. For example, in one embodiment, the annealing step is performed prior to forming the contact regions 222A, 222B of the third doping region 220.

Referring to FIG. 4B and FIG. 4C , in one embodiment, for example, the first doping region 102 of the bipolar junction transistor can be electrically connected to the collector voltage 134 by the contact region 106 . The second doped region 110 can be electrically connected to the base voltage 136 by the contact region 118. The third doped region 220 can be electrically connected to the emitter voltage 138 by the contact regions 222A, 222B. In other words, the first doping region 102 (including the first conductivity type such as the N conductivity type well region 104 and the contact region 106 is used as a collector. The second doping region 110 (including the second conductivity type such as P conductivity type) The well regions 112, 114, 116, the connection region 132 and the contact region 118 serve as a base. The third doping region 220 (including the first conductivity type, such as the N conductivity type contact regions 222A, 222B) is used as an emitter. The conductive structure 130 can be electrically connected to the structure voltage. In an embodiment, the structure voltage is coupled to the base voltage 136.

In an embodiment, the well regions 112, 114, 116 after diffusion and the formed junction regions 132 have a smaller doping concentration than the well regions 112, 114, 116 prior to diffusion, which can increase the bipolar junction transistor β gain. The formed connection region 132 can have a small size, which can increase the base resistance and increase the beta gain. Thus, in other words, embodiments can control the resulting connections by adjusting well regions 112, 114, 116 of second doped region 110, or by adjusting process parameters of diffusion well regions 112, 114, 116 (eg, annealing). Region 132, in turn, controls the beta gain of the bipolar junction transistor.

5A to 5C are respectively diagrams showing the bipolar junction transistors of FIGS. 3A to 3C in another embodiment, the well regions 112, 114, 116 of the second doping region 110 and the third doping. A schematic of the contact regions 222A, 222B of region 220 after being diffused. After the well regions 112, 114, 116 are diffused, the junction regions 132 forming the second doped regions 110 are formed. Connection zone 132 abuts between well zones 112, 114, 116 and has a second conductivity type. The bottom surface of the well regions 112, 114, 116 is lower than the bottom surface of the connection region 132. After the contact regions 222A, 222B are diffused, the connection regions 240 forming the third doping regions 220 are formed. The connection region 240 is adjacent between the contact regions 222A, 222B and has a first conductivity type. The connection region 240 of the third doping region 220 is located on the connection region 132 of the second doping region 110. The method of diffusing the contact regions 222A, 222B of the well regions 112, 114, 116 of the second doped region 110 and the third doped region 220 may include performing an annealing step. This annealing step can be performed at any suitable timing. For example, in one embodiment, the annealing step is performed after forming the contact regions 222A, 222B of the third doping region 220.

Referring to FIGS. 5B and 5C , the first doping region 102 of the bipolar junction transistor can be electrically connected to the collector voltage 134 by the contact region 106 . The second doped region 110 can be electrically connected to the base voltage 136 by the contact region 118. The third doped region 220 can be electrically connected to the emitter voltage 138 by the contact regions 222A, 222B. In other words, the first doped region 102 (including the first conductivity type, such as the N-conducting well region 104 and the contact region 106) is used as a collector. The second doped region 110 (including the second conductivity type, such as the P conductivity type well regions 112, 114, 116, the connection region 132, and the contact region 118) is used as a base. The third doping region 220 (including the first conductive type such as the N conductive type contact regions 222A, 222B and the connection region 240) functions as an emitter. The conductive structure 130 can be electrically connected to the structure voltage. In one embodiment, the structure voltage is coupled to the base voltage 136.

In an embodiment, the well regions 112, 114, 116 after diffusion and the formed junction regions 132 have a smaller doping concentration than the well regions 112, 114, 116 prior to diffusion, which can increase the bipolar junction transistor β gain. The formed connection region 132 can have a small size, which can increase the base resistance and increase the beta gain. Thus, in other words, embodiments can control the resulting connections by adjusting well regions 112, 114, 116 of second doped region 110, or by adjusting process parameters of diffusion well regions 112, 114, 116 (eg, annealing). Region 132, in turn, controls the beta gain of the bipolar junction transistor.

6A is a cross-sectional view of a bipolar junction transistor in accordance with an embodiment. The gate structure 142 is disposed on the well region 104 of the first doped region 102 between the well regions 112, 114, 116. The gate structure 142 includes a gate dielectric layer and a gate electrode layer disposed on the gate dielectric layer. The gate dielectric layer can include oxides, nitrides such as hafnium oxide, tantalum nitride, hafnium oxynitride, or other suitable materials. The gate electrode layer may comprise polysilicon, metal, metal halide, or other suitable material. The polycrystalline germanium can be formed, for example, in a single poly poly or double poly process.

FIG. 6B is a diagram showing the operation method of the bipolar junction transistor of FIG. 6A. A gate voltage is provided to the gate structure 142 to form a connection region 232 in the well region 104 (first conductivity type, such as N conductivity type) of the first doping region 102 below the gate structure 142 (second conductivity type such as P conductive type). Connection zone 232 abuts between well zones 112, 114, 116. In one embodiment, the gate voltage is coupled to the base voltage 136. Moreover, the first doping region 102 can be electrically connected to the collector voltage 134 by the contact region 106. The second doped region 110 can be electrically connected to the base voltage 136 by the contact region 118. The third doped region 220 can be electrically connected to the emitter voltage 138 by the contact regions 222A, 222B. In other words, the first doped region 102 (including the first conductivity type, such as the N-conducting well region 104 and the contact region 106) is used as a collector. The second doping region 110 (including the second conductivity type such as the P conductivity type well regions 112, 114, 116, the connection region 232 and the contact region 118 is used as the base. The third doping region 220 (including the first conductivity type) For example, the N-conductor contact regions 222A, 222B) are used as emitters. The conductive structure 130 can be electrically connected to the structure voltage. In one embodiment, the structure voltage is coupled to the base voltage 136.

In an embodiment, the varistor voltage is provided to the gate structure 142 to control the profile and carrier concentration of the connection region 232 formed in the well region 104 to achieve desired device characteristics. For example, the connection region 232 can be controlled to have a low carrier concentration, thereby increasing the beta gain of the bipolar junction transistor. Furthermore, the connection area 232 can be easily controlled to have a small size, thereby increasing the beta gain.

Figures 7 and 8 show the electrical curves of the bipolar junction transistors in the examples. From Figure 7, it is found that the current amplification of the bipolar junction transistor can reach about 3900 times. Furthermore, it is found from Fig. 8 that the Erleigh effect of the bipolar junction transistor is not serious.

Although the first conductivity type is an N conductivity type in the embodiment, and the second conductivity type is a P conductivity type. However, the disclosure is not limited thereto. In other embodiments, the first conductive type may be a P conductive type, and the second conductive type may be an N conductive type.

In conclusion, the present invention has been disclosed in the above preferred embodiments, and is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

102. . . First doped region

104, 112, 114, 116. . . Well area

106, 118, 122, 222A, 222B. . . Contact area

108. . . Base

110. . . Second doped region

120, 220. . . Third doped region

124. . . First top doped layer

126. . . Second top doped layer

128. . . Dielectric structure

130. . . Conductive structure

132, 232, 240. . . Connection area

134. . . Collector voltage

136. . . Base voltage

138. . . Emitter voltage

102. . . First doped region

104, 112, 114, 116. . . Well area

106, 118, 122. . . Contact area

108. . . Base

110. . . Second doped region

120. . . Third doped region

128. . . Dielectric structure

130. . . Conductive structure

134. . . Collector voltage

136. . . Base voltage

138. . . Emitter voltage

Claims (10)

A bipolar junction transistor comprising:
a first doped region having a first conductivity type;
a second doped region includes a plurality of well regions formed in the first doped region, wherein the well regions have a second conductivity type opposite to the first conductivity type, and the well regions are The first doped regions are separated from each other; and a third doped region having the first conductivity type, wherein the third doped region is formed in the well regions or formed between the well regions In a doped region. The bipolar junction transistor according to claim 1, wherein the second doping region further comprises a connection region adjacent to the well regions and having the second conductivity type, the wells The bottom surface of the zone is below the bottom surface of the joint zone. The bipolar junction transistor according to claim 2, wherein the third doping region comprises a contact region having the first conductivity type and located between the well region and the connection region, The contact area is located on the connection area. The bipolar junction transistor of claim 1, wherein the third doped region comprises a contact region having the first conductivity type and formed in the second doped region. A method of operating a bipolar junction transistor, wherein the bipolar junction transistor comprises:
a first doped region having a first conductivity type;
a second doped region includes a plurality of well regions formed in the first doped region, wherein the well regions have a second conductivity type opposite to the first conductivity type, and the well regions are The first doped regions are separated from each other; and a third doped region having the first conductivity type, wherein the third doped region is formed in the well regions or formed between the well regions In a doped region,
The method of operation includes:
Providing a collector voltage to the first doped region;
Providing a base voltage to the second doped region; and providing an emitter voltage to the third doped region. The method for operating a bipolar junction transistor according to claim 5, wherein the second doping region further comprises a connection region adjacent to the well regions and having the second conductivity type. The bottom surface of the well regions is lower than the bottom surface of the connection region, and the third doped region includes a contact region having the first conductivity type and located between the well regions and the connection region, the contact The zone is located on the connection zone. The method for operating a bipolar junction transistor according to claim 5, wherein the bipolar junction transistor further comprises a gate structure disposed on the first doped region between the well regions The method further includes providing a gate voltage to the gate structure to form a connection region in the first doped region under the gate structure, the connection region having the second conductivity type and adjoining the Between well areas. The method for operating a bipolar junction transistor according to claim 5, wherein the bipolar junction transistor further comprises:
a dielectric structure on the first doped region; and a conductive structure on the dielectric structure
The method further includes providing a structural voltage to the electrically conductive structure. A method for manufacturing a bipolar junction transistor, comprising:
Forming a plurality of well regions of a second doped region in a first doped region, wherein the first doped region has a first conductivity type, and the well regions have a first opposite to the first conductivity type a second conductivity type, wherein the well regions are separated from each other by the first doping region; and a third doping region is formed in the well regions or in the first doping region between the well regions, Wherein the third doping region has the first conductivity type. The method for manufacturing a bipolar junction transistor according to claim 9, further comprising performing an annealing step to diffuse the well regions to form a connection region of the second doping region adjacent to the wells Between the zones, wherein the junction zone has the second conductivity type, and the bottom surfaces of the well zones are lower than the bottom surface of the connection zone.