JPS58158965A - Semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a transistor of ultrafine size and high performance by forming an external terminal of electrodes as bonding pad on a pair of diagonal lines of a substrate and forming a pectinated active part and ohmic electrodes along the periphery of the substrate. CONSTITUTION:Diffused pattern of base and emitter and electrodes 4, 5 are formed at both sides along X- and Y-directions of a chip, and bonding pads 6, 7 lead from the electrodes have centers on a pair of diagonal lines of the chip. That is, the OF line of the substrate is used as a reference line, the main lines of the base and emitter are disposed perpendicularly or in parallel with the side of the pellet with matching seals AT1, AT2 formed at both ends of the substrate, and an interval P is formed in small size. The resistance between the base and the emitter is reduced due to the reduction of the interval P, the noise is reduced, power gain is raised, and a base area is reduced, thereby reducing the bonding capacity between the base the collector, high frequency characteristics are improved, and the improper shortcircuit between the emitter and the base can be reduced.

Description

[Detailed description of the invention] The present invention relates to a high frequency transistor.

Fig. 1 shows a high frequency transistor.

As shown in FIG. 1A, elongated diffusion regions of a P-type base 2 and an N+ Jul emitter 3 are alternately formed in the shape of a comb on the main surface of an NWS-substrate that becomes a collector, and each base region and each The person who made ohmic contact with the emitter region! Electrodes 4 and 5 made of films or the like are guided diagonally across the substrate to form bonding pads 6.7. In the conventional structure, as shown in the same figure, the base and emitter patterns constituting the teeth have been arranged along the diagonal direction of the substrate or in the direction perpendicular thereto.

This was done with the main focus on reducing manufacturing costs by arranging the active area of the transistor and the bonding pad in the smallest possible pellet size in order to effectively utilize the area of the semiconductor substrate. be.

However, in order to reduce the device capacitance in recently developed high-frequency transistors, the distance between the base and emitter is narrowed. In semiconductor devices that require alignment accuracy (base craft base - emitter base contact), it is difficult to achieve sufficient accuracy in the spacing of comb-shaped electrodes diagonal (45°) to the substrate side. .

The present invention has been made to eliminate the above-mentioned drawbacks, and its purpose is to develop a transistor with higher frequency characteristics and higher reliability.

The present invention will be described in detail below with reference to Examples.

Figure 11i2 shows a plane pattern showing the electrode arrangement of the high frequency transistor according to the present invention. In this transistor, the electrode patterns of the base 4 and emitter 5, which constitute the letter electrodes of the comb, are arranged in the scribing direction for cutting the substrate chip from the wafer, that is, on both sides of the chip, X and Y.
It is formed warped in the direction or perpendicular to the direction. Although not shown, base-emitter diffusion patterns are naturally formed on the substrate surface in the X and Y directions. On the other hand, the base
Ponding pad 6.7 derived from emitter electrode
According to the invention described in the above embodiments, the object of the invention is achieved for the following reasons: By inserting the base-emitter diffusion region and the electrode butter into the semiconductor substrate, the center is located on one diagonal of the substrate chip. The formation involves selective diffusion single-portion deposition with photoresist treatment in the form of a semiconductor wafer. During this photoresist mask alignment, the orientation flat (OF) of the semiconductor wafer is aligned with the reference line as shown in Figure 3, and alignment targets (AT,... AT,)
I look at it and try to match it. At this time, the alignment accuracy is achieved because it is easy to align the left, right, top, and bottom, and it is easy to see discrepancies.

When the main lines of the pattern are diagonal as shown in FIG. 1, it is difficult to distinguish between << and deviation. Therefore, as shown in FIG. 4 t8), (b), the direction of alignment deviation (bl and the direction of deviation tl of the active part pattern) do not match, and the following problem occurs. (II. The emitter J (electrode pattern) and the base (E? pattern) overlap and cause a short circuit. (2) Taking into consideration the deviation in (1) above, by widening the spacing (P) between the emitter and the base,
rbb' (resistance between base and emitter) increased, NF (noise) and PG (padded in) decreased, and due to the expansion of the base area, C8b (junction capacitance between pace collector) increased, and high frequency characteristics deteriorated. .

However, by arranging the main lines of the active part base and emitter perpendicularly or parallel to the sides of the pellet as in the present invention, the pattern misalignment and misalignment match those shown in FIG. 4(b).
It is possible to improve the alignment accuracy, reduce the emitter-base breakdown voltage gap, and reduce the base-emitter spacing P to lower NF, increase PG, and reduce Cob, resulting in higher frequencies. This made it possible to develop and manufacture a transistor with a wide range of characteristics. Further, since the bonding pads are arranged diagonally on the substrate chip, the substrate surface can be effectively utilized and the chip size can be reduced.

The present invention is particularly effective in improving the yield of fine high-frequency transistors.

[Brief explanation of drawings]

FIG. 1 is a plan view of an example of a high-frequency transistor, and FIG. 1A is an enlarged sectional view taken along line AA in FIG. FIG. 2 is a plan view showing an embodiment of a high-frequency transistor according to the present invention, FIG. 3 is a plan view showing a semiconductor wafer during photoresist mask alignment, and 4th Eta) and (b) show pattern deviation and alignment deviation. It is a principle explanatory diagram. 1...Nm&, 2...P base, 3...N+ emitter, 4...base electrode, 5...emitter electrode,
6, 7...ponding pad. Agent Patent Attorney Susuki 1) Toshiyuki 1 Figure 1A Figure 2 Figure 3f'4 Figure 4 (and 2-) θl

Claims (1)

[Scope of Claims] 1. A comb-toothed electrode in which different conductive regions alternately form a comb-toothed active part on the surface of a semiconductor substrate, and the comb-toothed electrode is in ohmic contact with the above regions. In the semiconductor device in which the outer terminal of each electrode is provided as a bonding pad on one diagonal line of the substrate, the comb-like active portion and the electrode in contact therewith are placed along the periphery of the semiconductor substrate. A semiconductor device characterized in that it is formed by 2. The semiconductor device according to claim 1, wherein the active regions formed alternately in the shape of comb teeth are a base and an emitter constituting a transistor. 3. The semiconductor device according to claim 1, wherein the active regions formed alternately in a comb-like shape are a source and a drain constituting a field effect transistor.