JPH0455330B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a semiconductor electrodeposition apparatus, and more particularly to improvements in an electrodeposition apparatus used for manufacturing glass packaging semiconductor devices.

[Technical background of the invention and its problems]

In order to improve the breakdown voltage of semiconductor elements, there is a technique of applying glass pinning to the joints. As shown in FIG. 1, a groove 2 is formed beyond the junction in one main surface (upper main surface) of a semiconductor substrate 1 on which regions of different conductivity types are formed, and as shown in FIG. As shown, after glass powder 3 is electrodeposited in the groove, the glass powder is heated and melted to achieve passivation of the glass layer (not shown). As shown in FIG. 3, the apparatus used for the electrodeposition described above includes a container 4 containing an electrodeposition liquid 5 in which glass powder is suspended, semiconductor substrates 1, 1 fixed with clips 6 in the container 4, and semiconductor substrates 1, 1 held in place facing each other. Electrodeposition is carried out by immersing the electrode body 7 provided in the semiconductor substrate for electrodeposition, and applying a voltage to the semiconductor substrate and the electrode body for a predetermined time using a power supply unit 8.

The conventional technology described above has the following problems.

(a) Since the semiconductor substrate is held by the clips at a part of the periphery of the semiconductor substrate, the holding is unstable and it is necessary to form electrodes in advance to make the semiconductor substrate conductive. For this reason, there was a problem that the amount of electrodeposited glass varied because the contact was unstable and changed.

(b) Next, since electrodeposition is performed with the liquid in a stationary state, the amount of glass electrodeposited varies in the direction of gravity as time passes, and semiconductor elements with a small amount will deteriorate withstand voltage, and if there is an excessive amount, they will break during the subsequent photolithography process. This caused defects and mask defects.

(c) Furthermore, based on the state of the electrodeposition solution described above, it was necessary to complete the work within a short time after preparing the electrodeposition solution, which caused a problem in workability.

In view of the above, an improved current supply support jig is shown in FIGS. 4 and 5. This supports the semiconductor substrate 1 on the electrically insulating plate 9 at three points around its periphery. That is, support members 10a, 10a', and 10b are provided on the electrically insulating plate to support the semiconductor substrate 7 at equal intervals around its periphery.
The supporting members 10a and 10a' protrude from the electrical insulating plate in an L-shape when viewed from the side.
b supports the semiconductor substrate against the electrically insulating plate by the pressing force of the spring 10c.

In addition, the support jig shown in FIGS. 6 to 8 includes a support body 11 made of a flexible material such as rubber, and a thin collar portion 11b that extends from the cup portion 11a and the open end thereof and protrudes from the cup portion 11a. The cup part has an electrode member 12 coaxially protruding therefrom with elasticity, a wiring 12a for energizing the electrode member 12, and a support tube 13 attached to the cup part perpendicularly to the axis thereof. This support tube is connected to a reduced pressure source, and is designed to reduce the pressure in the sealed space formed by applying the semiconductor substrate to the collar and hold it under suction. Since the brim is flexible and thin, it closely and tightly seals the periphery of the main surface of the semiconductor substrate, but when it is sucked under reduced pressure, it retreats and the semiconductor substrate is brought into pressure contact with the electrode member 12.

According to the above-mentioned support jig, problem (a) due to instability of support by the clip is solved, but there is a serious problem that the semiconductor substrate is broken by vacuum suction. Moreover, this trend has recently become a serious problem as semiconductor substrates have become larger in diameter.

[Purpose of the invention]

In view of the above-mentioned conventional problems, the present invention improves an electrodeposition apparatus for passivation of semiconductor devices.

[Summary of the invention]

A semiconductor electrodeposition apparatus according to the present invention is a semiconductor electrodeposition apparatus that performs electrodeposition by immersing a semiconductor substrate in which a power supply electrode is brought into contact with a suspension of glass powder while supporting it on an energization support jig. A power supply electrode flat part whose end face contacts the entire area of the semiconductor substrate supported by the semiconductor substrate except for the peripheral part of one main surface thereof, and a reduced pressure provided in connection with the center and peripheral parts of the power supply electrode flat part. A semiconductor electrodeposition apparatus characterized by a current supply support jig comprising a conductive path and a skirt part that contacts the peripheral part of the semiconductor substrate around the flat part of the power supply electrode and forms an airtight space, This semiconductor electrodeposition apparatus is characterized by being equipped with an energizing support jig, a stirring device consisting of a stirring bar for stirring a suspension, and a driving source thereof.

[Embodiments of the invention]

Next, one embodiment of the present invention will be explained in detail with reference to the drawings. In the description of one embodiment, parts that are the same as those of the prior art are designated by the same numbers in the drawings, and the description thereof will be omitted.

First, the device shown in FIG. 9 is based on the invention shown in FIG.
Shown in Figure 1. In each figure, reference numeral 21 denotes an electrode body made of metal, and its main body 21a is supplied with power from an electrodeposition power source and performs electrodeposition on a semiconductor substrate that is brought into close contact with one end thereof. That is, one end surface 21b is a circular shape that is slightly smaller than the semiconductor substrate, and a skirt portion 2 that widens toward the end is made of a flexible material such as silicone rubber around the periphery.
1f, and is in contact with the peripheral portion of the main surface of the semiconductor substrate to form an airtight space with the end surface 21b of the electrode body. Further, a decompression guide path 21c is provided through the main body 21a of this electrode body, and its terminal ends are an opening 21d in the center of the end face and an opening 2 in the peripheral part of the end face.
1e, the airtight space is reduced in pressure, and the semiconductor substrate is held.

Note that since the orientation flat portion at the periphery of the main surface of the semiconductor substrate is located above the skirt portion, it does not interfere with the formation of an airtight space, and the semiconductor substrate is held in close contact with the end surface of the electrode body by the reduced pressure. That will happen. Further, the portion of the electrode body that comes into contact with the electrodeposition liquid is coated in advance with an electrically insulating film 21g.

Next, as shown in FIG. 12, the second aspect of this invention is that a stirrer 22a is provided on the bottom of the electrodeposition liquid container 4 surrounded by a guide 23, and the upper surface of these is the most It is formed into a concave surface that is lower. Further, the stirring bar 22a is connected to a stirring drive source 22c by a drive shaft 22b that penetrates the bottom of the container in a liquid-tight manner, thereby forming a stirring device 22.

The above-mentioned stirring device is driven at least every time the electrodeposition operation is performed to cause the glass powder to settle or to stir up the glass powder that is settling, thereby restoring the concentration and non-uniformity of the liquid.

〔Effect of the invention〕

According to the present invention, there is a remarkable advantage that the novel structure of the electrode body allows semiconductor substrates, especially large-diameter ones, to be firmly held without being damaged. Furthermore, even if a contact electrode is provided on the main surface of the semiconductor substrate opposite to the main surface on which passivation is applied and glass electrodeposition is performed, no glass powder is attached to the electrode, so the operation can be performed many times.

Next, according to the second invention, the amount of electrodeposited glass fluctuates due to settling of glass particles in the glass liquid and the concentration decreases, but this can be restored by stirring. This method has the advantage of keeping the amount of glass electrodeposited constant and significantly improving workability.

[Brief explanation of drawings]

1 and 2 are cross-sectional views of a semiconductor element, FIG. 3 is a cross-sectional view of a conventional electrodeposition apparatus, FIGS. 4 and 5 are a support jig of a conventional example, and FIG. 4 is a top view. Figure 5 is a side view, Figures 6 to 8 show an example of a conventional support jig, Figure 6 is a cross-sectional view, Figure 7 is a top view, and Figure 8 is a cross-section showing the state of use. FIG. 9 and subsequent figures relate to embodiments of this invention,
FIG. 9 is a sectional view of an electrodeposition apparatus according to an embodiment of the first invention, FIGS. 10 and 11 are a support jig of an embodiment, FIG. 10 is a top view, and FIG. 11 is a sectional view. ,
FIG. 12 is a sectional view of a support jig according to an embodiment of the second invention. 5...Glass electrodeposition liquid, 21...Support jig, 21
a... Main body of the electrode body, 21b... End surface of the electrode body,
21c... Decompression guide of electrode body, 21d, 21e...
. . . Opening of the pressure reduction channel, 21f . . . Skirt portion of the support jig, 22 . . . Stirring device, 22a .

Claims (1)

[Scope of Claims] 1. In a semiconductor electrodeposition apparatus that performs immersion electrodeposition by supporting a semiconductor substrate with a power supply electrode in contact with a suspension of glass powder on an energizing support jig, the end face of the power supply electrode is a flat power feeding electrode portion that contacts the entire area of the semiconductor substrate supported by the semiconductor substrate except for the peripheral portion of one principal surface thereof; and a decompression guide provided in connection with the center and peripheral portions of the flat surface portion of the power feeding electrode; A semiconductor electrodeposition apparatus comprising: a skirt portion that contacts the peripheral portion of the semiconductor substrate to form an airtight space around the flat portion of the power feeding electrode; 2. In a semiconductor electrodeposition apparatus that performs immersion electrodeposition by supporting a semiconductor substrate with a power supply electrode in contact with a suspension of glass powder on an energizing support jig, the semiconductor substrate on which the end face of the power supply electrode is supported. a flat surface portion of the power feeding electrode that contacts the entire area except for the peripheral portion of one principal surface thereof, a depressurization conduit provided in connection with the center and peripheral portions of the flat surface portion of the power feeding electrode, and a flat surface of the power feeding electrode. an energizing support jig having a skirt portion that contacts the peripheral portion of the semiconductor substrate to form an airtight space around the semiconductor substrate; a stirring device comprising a stirring bar for stirring the suspension and a driving source thereof; A semiconductor electrodeposition device characterized by comprising: