JPS63143867A - Semiconductor integrated circuit device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a Shishitkey barrier diode clamped transistor, and particularly to one in which output leakage current is reduced.

[Conventional technology]

As a conventional Schottky barrier diode transistor, for example, [85 Mitsubishi Semiconductor Data Book Bipolar Digital IC<LSTTL>&l (1
The structure shown in "Page 12)" will be taken as an example and explained with reference to FIG. Figure 2+8) is a plan view, and Figure 2+8) is a side view. Moreover, FIG. 3 is its equivalent circuit diagram.

In the figure, l is a collector part N-type semiconductor layer, 2 is a base part P-type semiconductor layer, 3 is an emitter part N-type semiconductor layer, 4 is a Schottky barrier diode (hereinafter referred to as SBD) part, and 5 is a buried collector layer. , 6 is an N-type semiconductor epitaxial layer, 7 is a contact hole for forming the SBD part 4 and a base contact, IO is a corner part of the contact hole 7, 11 is an SBD, , 12 is an NPN layer)
transistor, 9 is metal for wiring, base part is NPN)
The base of transistor 12 and the anode of 5BDII are short-circuited. 8 is an oxide film for insulating between the wiring metal 9 and the semiconductor surface.

Next, the operation will be explained.

Since the collector potential of the SBD transistor is clamped at 5BDII when the NPN transistor 12 is turned on, the storage time of the transistor can be shortened.

However, if there is a leak in the reverse characteristics of 5BDII,
Collector leakage current I is 1” It*, +Ic = rtami++ fiyt
'Itsam= I Leak (1+h re), and if h re2100, I=100XIL
OK, and even if I Rank is minute, the leakage current of the collector cannot be ignored.

Generally, the leakage current of SBD is caused by the manufacturing method, and most of the leakage current occurs at the outer periphery of the contact hole 7, and especially at the corner 10 of the contact hole 7.
The leakage current is overwhelmingly large.

[Problem that the invention seeks to solve]

Since the conventional SBD (conventional SBD) transistor is configured as described above, the leakage current at the outer periphery of the contact hole, especially at the corner, becomes dominant in the leakage current of the entire SBD, and the leakage current is smaller than that of a PN diode. is more than one order of magnitude larger, and there was a problem in that the collector leakage current of the SBD transistor was large.

The present invention was made to solve the above-mentioned problems, and an object of the present invention is to obtain an SBD transistor that can reduce collector leakage current without increasing the pattern size.

[Means for solving problems]

In the semiconductor integrated circuit device according to the present invention, a corner portion of a contact hole for forming an SBD is shaped like an arc. ,.

[Effect]

In this invention, since the corner portion of the contact hole for forming the SBD is shaped like an arc,
There is no concentrated area of leakage current, and the collector leakage current can be reduced.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 (al and mountain) is a 5B according to an embodiment of the present invention.
D) A plan view and a sectional view of a transistor. In the figure, the same reference numerals as in FIG. It has a shape.

In a semiconductor integrated circuit device having such a configuration, by making the corner portion 10 of the contact hole 7 into an arc shape, the leakage current is overwhelmingly large (because there is no acute corner portion where the current flows, the leakage current is significantly increased). There is no current concentration area, and the collector leakage current can be reduced.Also, since the corner portion 10 of the contact hole 7 is only shaped into an arc, there is no need to increase the pattern size, and furthermore, it is possible to reduce the collector leakage current. Similarly,
Mask work can be done easily.

〔Effect of the invention〕

As described above, according to the semiconductor integrated circuit device of the present invention, the corner portion of the contact hole for forming the SBD is formed into an arc shape, so that the leakage current of the collector can be reduced without increasing the transistor size. There is an effect that can be achieved.

[Brief explanation of the drawing]

Figure 1 (1m) is a plan view showing an SBD transistor according to an embodiment of the present invention, and Figure 1 ('b) is its (a).
- (11) Cross-sectional view, Figure 2 (a) is a top view showing the conventional SBD transistor, Figure 2 (b) is its (71)
-(d) Cross-sectional view, Figure 3 shows the SBD of the conventional and this embodiment.
) is a circuit diagram showing a transistor. In the figure, l is a collector part N-type semiconductor layer, 2 is a base part P-type semiconductor layer, 3 is an emitter part N-type semiconductor layer, and 4 is S
BD part, 5 is N type semiconductor layer for buried collector, 6 is N
type semiconductor epitaxial layer, 7 is a contact hole, 8
1 is an oxide film, 9 is a wiring metal, 10 is a corner portion, 11 is an SBD', and 12 is an NPN transistor. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) The Schottky barrier diode is formed in a Schottky barrier diode clamp transistor in which the base of an NPN transistor is connected to the anode of a Schottky barrier diode, and the collector of the transistor is connected to the cathode of the Schottky barrier diode. 1. A semiconductor integrated circuit device, wherein a contact hole for contacting the semiconductor device has an arc-shaped corner portion.