JPS61107753A - Semiconductor device - Google Patents

Abstract

PURPOSE:To simplify the constitution of a semiconductor device by using the same silicon substrate as an external leading-out electrode for a device with two different conduction type regions and electrically insulating the substrate by an internal P-N junction. CONSTITUTION:An external leading-out electrode plate 7' consists of an silicon substrate having low resistance, and a P type diffusion region 8 is formed where corresponding to a base region 3. An N<+> diffusion region P is shaped into the P type diffusion region 8. The N<+> diffusion regions 9 are all connected in the electrode plate 7'. A stepped section 10 is formed to one part of the external leading-out electrode plate 7' composed of the silicon substrate, and a lead wire 12, etc. are lead out of an electrode 11 shaped onto the N<+> region 9 in the stepped section 10.

Description

[Detailed description of the invention] [Industrial use! P] This invention relates to an external extraction electrode of a semiconductor device, in particular, two mutually different regions are arranged in a plurality of island shapes on one main surface side of a semiconductor pellet, and each electrode metal provided in this common region and an electrical The present invention relates to a semiconductor device with an improved structure of an external lead-out electrode that is connected to the outside.

[Prior Art] In large-capacity semiconductor devices such as power transistors, Darlington transistors, and gate turn-off thyristors (GTOs), two mutually different regions are generally divided into island shapes on one main surface of a semiconductor pellet. The electrode metal on this region also has a fine and complicated shape. Such electrode metals are provided with external lead-out electrodes that are electrically connected to them, but since the electrode metals have minute and complicated shapes as mentioned above, the following measures are generally taken. .

■ It is difficult to attach external lead electrodes directly to electrode metal with a complex pattern that is divided into multiple parts.
Electrical connections are made between each island using aluminum (Affi) wires and gold wires (AU) using wire bonding, ultrasonic, thermocompression bonding, etc., and electrical connections are made from any one island to the outside. An external extraction electrode is provided.

- A metal plate is microfabricated to match the island pattern of the electrode metal on the conductivity type region, and an external lead electrode is attached via this metal plate.

[Problem to be solved by the invention] In the case of (2) above, the larger the number of divided islands, the larger the number of wiring wires, which may lead to reliability problems and the problem of multiple For products that incorporate semiconductor devices, it is necessary to electrically insulate the wires from each other, which further complicates the overall configuration and increases W4 assembly work.
There was a problem that clutter etc. could not be avoided.

In addition, in the case of (■) above, firstly, it is extremely difficult to perform microfabrication to match the pattern shape of the metal plate, and furthermore, it is difficult to align both patterns during assembly, and in extreme cases, short circuit accidents due to misalignment may occur. There was a problem.

This invention was made to solve the above-mentioned problems, and provides a semiconductor device having an external extraction electrode structure that can be easily taken out from two regions of different conductivity types on the surface of a semiconductor pellet. The purpose is to do something.

[Means for Solving the Problems] A semiconductor device according to the present invention provides an external lead electrode plate made of a single silicon substrate for two regions of different conductivity types exposed on the whole surface side of a semiconductor pellet. ,
It is placed on the permanent surface side of the semiconductor pellet.

[Function] P-N junctions are formed in a silicon substrate serving as an externally drawn electrode plate, and electrodes are drawn out from different regions on the whole surface side of a semiconductor pellet using a single silicon substrate while insulating each other.

[Example] FIG. 1 is a cross-sectional view schematically showing a semiconductor device according to the present invention.

In the figure, the semiconductor pellet (1) is heated. □, yo,, 7e, ka □□5:/9. ．． 9 t'G □; Collector region (2), base region (3), island-shaped emitter region (4) separated from each other within this base region (3)
is formed.

In this way, a base region (3) and an emitter region (4) appear on the same plane on the -main surface side of the semiconductor pellet (1) in a form that is intertwined with each other. Metal electrodes (5) are formed on the base region (3) and emitter region on the same plane, respectively.
), (6) are provided, and a metal electrode (7) is also provided on the collector region on the opposite main surface side.

An external extraction electrode plate (7') is provided on the metal electrode (6) of the emitter area (4), and the material of this external extraction electrode plate (7') is a silicon substrate, and the base area (
3) and metal electrodes (5), (6) of the emitter region (4).
) is formed in a shape that matches the pattern shape.

That is, the external lead electrode plate (7) is made of a low-resistance silicon substrate, and has a specific resistance of, for example, 3 to 15/1000Ω.
Using an N-type silicon substrate with a Cl11 thickness of 300 μm, a P-type diffusion region (8) is formed at a position corresponding to the base region (3) by ordinary photolithography technology, selective diffusion Fh, etc., and then this P-type There are N10 diffusion regions (
9).

The N+ diffusion regions (9) are all connected within the electrode plate (7').

The purpose of creating this P-N junction is to form an external lead electrode that is insulated and separated from the emitter region [(4).

A step (10) is provided in a part of the external lead electrode plate (7') made of a silicon substrate, and a lead wire (12) is connected from the electrode (11) provided on the N+ region 9) of this step (10).
etc. The base electrode contacts the outside through a path of base region M (4) - electrode metal B (6) - electrode metal (14) - N0 area of electrode plate (7') - electrode metal (15).

Gold B electrodes are also placed on the surface of the external lead electrode plate (7) made of a silicon substrate in accordance with the pattern shapes of the gold ff1M (5) and (6) above the base region (3) and emitter region (4). (13) and (14) are formed, and these metal electrodes (5), (13) and (6), (14) are superimposed, for example, through a tin-lead (Sn-Pb)-based low-temperature solder, respectively. The externally drawn electrode plate (7 pieces) and the semiconductor pellet (1) are bonded together through a furnace or the like.

Note that the externally drawn electrode plate (7') is bonded or pressed to an electrode post (not shown) made of copper or the like arranged on the outside thereof.

In this invention, the external lead electrode plate (7') is made of a silicon substrate as described above, but since the thickness of the silicon substrate used is as thin as 200 to 300 μ■, it is not practical in terms of resistivity. 1 There are almost no problems.

That is, specific resistance 1.2X10-2Ω/C11 thickness 30
Resistivity per unit cross-sectional area (cm2) of 0μm is 3.6X
It is about 10-4Ω, and there is almost no problem.

Further, this resistance valve serves as a kind of balance bottle in power transistors, Darlington transistors, etc., and has the effect of preventing current concentration to a specific location and improving the electrical characteristics of the semiconductor device.

Furthermore, in conventional devices that are drawn from one or multiple locations, if the pattern of the electrode metal is complex, lateral resistance occurs between each electrode metal and the conductive region, causing a drop in current characteristics. However, in the case of the above embodiment, this does not occur because all the electrodes are in metal contact.

Furthermore, although the external lead electrodes of the base region (3) and the emitter region 14 (4) are formed of the same silicon substrate, the withstand voltage between the base and the emitter is, for example, about 20V, and therefore this embodiment By creating such a P-N junction, it is possible to sufficiently insulate and separate the two.

Although the above embodiment was explained using a power transistor as an example, it can of course be applied to other semiconductor devices, such as a GTO, or a device in which multiple semiconductor devices are built into one semiconductor pellet. It can also be used for Further, the external lead electrode made of a silicon substrate does not necessarily have to be integral, and can be divided into a plurality of parts.

[Effects of the Invention] As described above, the present invention uses the same silicon substrate as the external lead electrode of a semiconductor pellet having two different conductivity type regions on the -1 plane, and electrically conducts the semiconductor pellet by an internal P-N junction. This structure simplifies the structure of the semiconductor device, and since the external lead electrodes are formed on a silicon substrate, photolithography technology and
Microfabrication can be easily performed using etching processing technology, and an external lead-out electrode having a shape matching the pattern shape can be easily formed. Moreover, since the external lead electrode formed in this case is connected to the electrode metal of the semiconductor pellet on the entire surface, lateral resistance does not occur unlike in the conventional case, and power transistors and Darlington transistors can be efficiently connected from the entire emitter region. Current is collected, and this improves electrical characteristics, and in thyristors such as GTO, has effects such as improved surge resistance ω.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a schematic structure of a semiconductor device showing an embodiment of the present invention. In the figure, (1) is a semiconductor pellet, (2) is a collector region, (3) is a base region, (
4) is the emitter region, (5). (6) is a metal electrode, (7') is an external lead electrode plate made of a silicon substrate, (8) is a P type region, (9) is an N medium region, and (13) and (14) are metal electrodes. applicant

Claims (1)

[Claims] In a semiconductor device in which two regions of different conductivity types are formed on one main surface side of a semiconductor pellet, electrode metals are provided on these regions, and external lead electrodes are provided on each of these electrode metals, the external lead electrodes are provided. An electrode plate made of a single silicon substrate with a P-N junction provided therein to electrically insulate two regions of different conductivity types was placed on one main surface side of the semiconductor pellet. A semiconductor device characterized by: