JPS5925271A - Transistor - Google Patents

Abstract

PURPOSE:To obtain a transistor of an emitter mesh structure of large secondary breakdown withstand voltage by a method wherein ring-shaped current block regions are provided in base contact regions. CONSTITUTION:The transistor is composed of a collector region 1 consisting of an N type semiconductor substrate, a P type base region 2, and an N type mesh emitter region 3. Many circular base contact regions 4 are dotted in the region 3, and the N type ring-shaped current block regions 5 are formed in the regions 4. A base electrode ohmic-contacts the regions 4 in the regions 5, or are brought into ohmic contact with both of regions 5 and the regions 4 therein. The base current from the electrode 6 is restricted by the regions 5 and does not flow into the surface of the region 3, accordingly flows into the bottom surface of the region 3. As a result, the side surface of the region 3 becomes inactive, and then the secondary breakdown withstand voltage can be largely improved.

Description

DETAILED DESCRIPTION OF THE INVENTION 1) Field of the Invention The present invention relates to improvements in transistors, particularly transistors having a mesh emitter structure.

Same prior art 1:r Menyuemizuta sliding structure was considered as a structure to increase the current capacity of the transistor. The mesh emitter structure is shown in FIG. 1 with base regions (2j, 2j,
There is a mesh-like emitter region (3), and inside the emitter region (3) there is a round base contact head JJJ, +41
There are many scattered places. The r-mitter electrode is in ohmic contact with the mesh-like emitter region (3), and the base electrode is in ohmic contact with each base contour (4).

In the above supplement, the mesh-like C-mitter region 13) can only increase the emitter area, which is useful for reducing the chip area for obtaining the same emitter area.

However, in a transistor with such an emitter mesh structure, the base contact region (
41 is surrounded by an active emitter region 13), there is a drawback that secondary breakdown occurs at the surface.

1 DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and by providing a scarlet 1-shaped heavy flow masticating region (5) in the base contact region (4), it is possible to improve the secondary yield strength. The aim is to realize a transistor with a large emitter mesh structure.

Embodiments of the Invention A transistor according to the present invention has a collector fir=IJdt[I,
P-type base region [21, N-type slightly spiky emitter region (31, 41'ft), emitter region (31
A large number of round base contact regions (4) are scattered within the interior, and a J-shaped circular current 1! J
l tlz region (5) to each base contact region (4)
form within.

The annular current blocking region (5) is, for example, a base contact with a diameter of 200.4') 56 W 30. #20.1111] are spaced apart. As a result, a base contact region (4) with a diameter of 1 [1 (J, #I) can be secured within the annular current blocking region (5).The annular current ■positive region (5) is the emitter region (3). At the same time (two-diffusion formation is sufficient).

The base electrode (61 is in ohmic contact with the annular current blocker as shown in FIG. 3).

According to the transistor of the mesh emitter structure of the present invention described above, the base current from the base' viewing pole (6) is regulated by the annular current blocking region (5) and the surface of the blind emitter region Jffl131 is regulated by the annular current blocking region (5). It does not flow into the parts, and the Emida color is 1
Castle (3) Flows to the bottom. As a result, the sides of 31 in the c-mitter working area become inactive, and the secondary yielding claws face 1:
,can.

Figure 4 is a characteristic diagram showing the secondary yield resistance 11, and the X axis shows C
The temperature of the PN junction (VOB) is plotted on the Y-axis, and the change in voltage (△VBF) is plotted on the Y-axis. The characteristics are shown by the dotted line.I-Compared to the conventional one, the secondary FF's fall resistance has been expanded to approximately twice that of the conventional one.Industrial Applicability A: According to the invention In a transistor of 41'6 structure, a power transistor with a high breakdown voltage can be realized by the operation of the mesh 1 limiter.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional perspective view for explaining a conventional example, FIG. 2 is a cross-sectional perspective view for explaining the present invention, and FIG. 3 is a cross-sectional view for explaining a transistor of the present invention having 119 electrodes. FIG. 2 is a characteristic diagram illustrating both the conventional and A) invention secondary yielding classes. tllljko” ri9 fi J1.!l+, +2
1&;t He-hui] n castle, +:11 &-! , r-
Mitsutaro's theory v, (4) is base contact f Hakusai,
t51c o Annular reformer 1111 stop 6 self-extrusion, (fil is the base electrode. 5f Figure 3 to Figure 4 cB

Claims (1)

[Claims] 1. A collector region, a base region, and an emitter region are provided, and a υ+, c emitter region is provided on almost the entire surface of the 2iJ base region, and n1Ji! 12 The contact region of the base region J is 1)) The transistor arranged in a number of islands in the J L-mitter region (2) The contact region of the base region is the same as the J-J C-mitter region. A ji-type ring 4 large current β blocking region is provided, and υ is provided in the ring-shaped current blocking region.
A transistor characterized in that a base electrode is in ohmic contact with a contact region.