JPS59169178A - Semiconductor device - Google Patents

Abstract

PURPOSE:To prevent a shortcircuit between the gate electrode and the cathode electrode of a high velocity thyristor by forming an escape such as a through hole or a slot having a profile slightly larger than the gate electrode on a contacting electrode plate opposed to the gate electrode. CONSTITUTION:A through hole 8 having the same shape of the profile slightly larger than the gate electrode 2 is provided at the position opposed to the gate electrode 2 of a contacting electrode plate 5. It is not necessary to form a recess on the main surface of a silicon substrate 1 and to dispose the gate electrode 2. The gate electrode 2 is not only contacted directly with the plate 5, but a projection or foreign material is not passed through the hole 8 of the plate 5. The plate 5 is mounted by utilizing the hole 8 while confirming so as to be coincident to the position of the electrode 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a polarization structure for a semiconductor device including roughly shaped gates.

[Prior art and its problems]

Example B shows a plan view showing the surface shape of a high-speed silice element in FIG. 1, and FIG. 2 shows an enlarged sectional view taken along the line A-A in FIG. 1 and 2, the semiconductor substrate 1 has a complex-shaped gate electrode 2 and cathode electrode 3 on its main surface. Here, the gate electrode 2 and the cathode electrode 3 (
! The two magnetic poles are usually arranged separately to prevent permanent electrical short-circuiting. 4 is a first stage gate electrode.

Further, above the cathode electrode 3, as shown in FIG. 3, a contact electrode 5 made of a conductive metal and having a smooth surface is brought into contact. The means for arranging the gate '#M, pole 2 and cathode electrode 3 so that no electrical short circuit occurs is shown in FIG. 2 or 3. For example, if the main surface of the silicon substrate 1 is an uneven surface A step is formed by an etching process using a chemical or the like, and a gate electrode 2 made of an aluminum vapor-deposited film is formed in the recessed part of the silicon substrate 1, and a step made of an aluminum vapor-deposited film is also formed on the outermost surface of the silicon substrate 1. This is done by providing a cathode electrode 3 of In this way silicon A
Due to the difference in height of the uneven surface provided on the main surface of M1, a space insulation part is created between the gate electrode 2 and the contact electrode plate 5, and the gate electrode 2 connects the cathode that is in contact with the contact electrode plate 5 with the electrode. This means that a state of physical insulation is maintained.

However, due to this structure, the disadvantage is that a curved number inevitably occurs. The depth dimension of the recess formed on O1 is 0.02 + nm
This is accompanied by difficulties in processing as it has to be controlled. For example, if the depth of the recess on the main surface of the processed silicon substrate 1 is shallower than the specified dimension, this may be due to poor correlation between the gate electrode 2 and the photomask, as shown in Figure 4. When the protrusion 6 is formed, this protrusion 6
may come into contact with the contact electrode plate 5, resulting in an electrical short circuit between the gate electrode 2 and the cathode 1 pole 3. In addition, as shown in Figure 5, if foreign matter 7 such as metal particles gets mixed into the recesses formed on the surface of the silicon base 1 soil during the manufacturing process, the electrically conductive foreign matter will
Gate electrode 2 and contact electrode &5 come into contact, causing a short circuit between the gate and cathode parents.

[Purpose of the invention]

The present invention eliminates the above-mentioned drawbacks and provides an electrode that permanently maintains a stable operating state without causing any gaseous short circuit between two or more electrodes provided in a semiconductor device. This is to provide a method for creating a structure.

[Key points of the invention]

For example, in order to prevent a short circuit between the gate, cathode, and parent electrodes of a high-speed thyristor, the present invention provides a contact plate (a ring slightly thicker than the gate electrode) on the side facing the gate electrode.
This is achieved by providing a recess such as a through hole or groove with an S.

[Embodiments of the invention]

The explanation will be based on 91J of the present invention.

FIG. 6 is a cross-cut diagram showing the electrodes 44 of two high-speed thyristors, similar to FIGS. 2 to 5, and the same symbols as in FIGS. 2 to 5 are represented by the same names. . In the present invention,
Figure 5 (In order to prevent the gate polarization 2 and the contact electrode plate 5 from coming into contact with each other, the contact electrode plate 5 is gated) 1
A through hole 8 is provided at a portion opposite to the gate H4 pole 2 and has the same contour shape as that of the gate H4 pole. 2, and the thickness of the electrically conductive material used as the contact electrode plate 5 is 01 to 0.5 mm, which is the main problem of the silicon substrate l, which was considered a drawback of the conventional method. Since the difference in height of the unevenness provided on the surface is much larger than the height difference of 0.02 x 0.01, even if the gate electrode (the protrusion 6 in Fig. 4 mentioned above or the foreign matter 7 in Fig. 4 is mixed in) Even if the thickness of gate region pole 2 is 0.
02+m is enough to deal with ζ. That is, contact with the gate electrode 2 'F1! Pole plate 5. Not only will there be no direct contact, but there will also be contact between protrusions and foreign objects.79! The through hole 8 of the IT polar plate 5 will not be cut out. The contact electrode plate 5 can be attached using the through hole 8 while checking that it matches the position of the gate electrode 2.

FIG. 7 shows a modification of FIG. 6. The difference between FIG. 7 and FIG. 6 is that the thickness of the contact electrode plate 5 is made sufficiently thick and a groove 9 having the same outline as the gate electrode 2 is provided instead of a through hole 8. This groove 9 is much easier to form than the formation of a concave portion in a conventional semiconductor substrate, which is difficult to control in size. If the depth of the groove 9 is set to 0.01 to 0.5 mm, the effect is similar to that shown in FIG. The thickness of the contact electrode plate 5 itself is 1 to 3 mm. For example, in a flat type high-speed cylisk, the contact electrode plate 5 is pressed into contact for the first time after it is housed in a case, and the pressure contact plate 5 is not always restrained, so the distance is 0.1 to 0.5 m. If the contact polarization plate 5 has a thickness of 1 to 3 mm as shown in Figure 7, it is safe to use a reinforcing plate to prevent rotation during handling. Since the contact electrode plate 5 can sufficiently function as a sleeve against rotation, it is not necessary to take measures to prevent the contact electrode plate 5 from rotating. Naturally, therefore, a secondary effect is that the number of parts is reduced, and the contact electrode plate 5 can be assembled using a separately provided positioning hole (not shown).

〔Effect of the invention〕

As explained above, according to the present invention, there is no need for the extremely laborious and troublesome mechanical work to form the four parts on the main surface of the silicon substrate, and the depth is difficult to control. The through holes or grooves provided in the contact electrode plate can be arranged to provide a sufficiently large distance between the gate electrode and the contact electrode plate, so that unexpected disadvantages such as random foreign matter can be avoided. Even if such a situation were to occur, it is certain that an electrical short-circuit force between the gate electrode and the cathode electrode will not occur for three periods, and the semiconductor device using the present invention can be operated stably. Although the non-invention was explained in connection with high-speed silicon risk, it can also be applied to transistors and the like.

[Brief explanation of drawings]

Figure 1 is a plan view showing the polarization structure of a high-speed thyristor, Figure 2 is an enlarged sectional view, Figure 3 is a sectional view of both contact electrodes, and Figures 4 and 5 are the polarization structure of the high-speed thyristor. 6 and 7 are cross-sectional views showing the short-circuited state, and FIGS. 6 and 7 are cross-sectional views including the electrode of the present invention. 1: Semiconductor lli, &, 2: Gut'g pole, 3: Cathode polarization, 5: Contact electrode, 6: Projection, 7: Foreign matter, 8: Through hole, 9: Groove. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] l) A semiconductor device comprising a first electrode layer that contacts the contact electrode plate on the main surface of the semiconductor substrate, and a second electrode layer that does not contact the contact plate; 1. A semiconductor device comprising a contact plate having a relief portion having a slightly larger outline than the second electrode layer at a location facing the second electrode layer.