JPH027527A - Transistor - Google Patents

Abstract

PURPOSE:To suppress the increase of a base resistance and improve an operation speed and a current amplification factor by a method wherein a first wiring which is directly brought into contact with a base and a second wiring which is directly brought into contact with an emitter are separated from each other with specific insulating films. CONSTITUTION:A first wiring 106 made of semiconductor material is directly brought into contact with a base 104 and extended to the neighborhood of an emitter 105. A second wiring 109 made of semiconductor material is directly brought into contact with the emitter 105. The first wiring 106 and the second wiring 109 are separated from each other with an insulating film 107 which is provided on the first wiring 106 and has the same pattern as the first wiring 106 and a side wall insulating film 108 which is formed by whole surface coating and whole surface etching before the second wiring 109 is formed. With this construction, a base resistance is significantly reduced. With this constitution, a base impurity concentration can be reduced and a base length can be shortened and a high performance can be achieved easily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of a bipolar transistor in a semiconductor device.

[Prior Art 1] A cross section of a conventional bipolar transistor is shown in FIG. 2. In the past, as can be seen from FIG. 2, an electrode was taken out from a base 204 by a metal wiring 210.

Also, in this prior art example, the emitter electrode is made of 209 polycrystalline silicon to form a shallow emitter junction.

[Problem to be solved by the invention]

In order to improve the performance of bipolar transistors, there are various methods tailored to various characteristics, and the present invention particularly focuses on improving speed and current tank capacity.

- As a general rule, to increase the speed, it is possible to shorten the running time in the base, reduce the base concentration, or
The pace length can be shortened, and by doing so, the current bath efficiency (hfe) can also be improved. However, this structural change also has the disadvantage of increasing base resistance. In particular, in the conventional structure shown in FIG. 2, the base electrode 210
The distance between the emitter 205 and the emitter 205 is long, which exacerbates this problem.

The present invention was devised for the purpose of suppressing the increase in base resistance of the conventional structure and improving speed and current amplification rate.

[Means for Solving the Problems J] The present invention uses two layers of wiring material containing a semiconductor material, and the first layer is brought into direct contact with the base region and close to the emitter, thereby reducing the base resistance. The second layer serves as an emitter electrode as in the conventional example. In addition, in order to separate the first and second layer wiring materials, an insulating film and a second layer are formed on the first layer wiring material and have the same pattern as the first layer wiring material.
Before forming the wiring material, a sidewall insulating film is deposited on the entire surface and formed by etching on the entire surface.

[Example] The structure of the present invention will be explained with reference to the sectional view of FIG. A first wiring material made of a semiconductor material is shown at 106, and the wiring material does not come into direct contact with the base 104, but is wired up to the vicinity of the emitter 105.

Further, the second wiring material 109 is directly connected to the emitter 105. Also, the first wiring material 106 and the second wiring material 109
Now, the process for realizing the present invention will be explained using the process cross-sectional view of FIG.

In FIG. 3, only the parts for explaining the present invention are shown, and the collector, shrimp layer, etc. are not shown. First, in FIG. 3(A), after forming the element isolation 302, the base region 303 is Form. Thereafter, the first wiring material 304 and the insulating film 305 are deposited on the part that will become the zero-order emitter region by photolithography and etching, and then the second insulating film 306 is covered over the entire surface. wear. (B) Next, when 306 is etched on the entire surface (
C) A sidewall film can be obtained as shown in FIG. 307. After this, impurity implantation for the emitter is performed as in step 308, and a second wiring material is deposited.

Thereafter, the structure shown in FIG. 1 is obtained by normal steps.

[Effects of the Invention] As can be seen from FIG. 1, since the first wiring material 106 can be brought as close as possible to the emitter 105, the base resistance can be considerably reduced. This makes it easy to lower the base concentration and shorten the base length to improve performance. Furthermore, since the width of the sidewall 108 can be controlled by the film thickness shown in FIG. 3(B), one of the advantages of this structure is that it can be freely selected according to the lateral spread of the diffusion layer of the emitter 105. It is one.

Figure 1

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of the present invention. FIG. 2 is a sectional view showing a conventional structure. FIGS. 3(A) to 3(C) are step-by-step cross-sectional views showing the manufacturing steps of the present invention. Applicant: Seiko Epson Co., Ltd. Agent Patent Attorney: Masayoshi Kamiyanagi (and 1 other person) Figure 2

Claims (1)

[Claims] In a bipolar transistor, a base region is directly electrically connected to a first wiring material whose component is a semiconductor material, and an emitter region is electrically connected to a second wiring material whose component is a semiconductor material. are connected to each other, and the first and second wiring materials are formed by forming an insulating film on top of the first wiring material and having the same pattern as the first wiring material, and before forming the second wiring material. A transistor characterized in that it is separated by a sidewall insulating film formed by etching the entire surface after being deposited on the entire surface.