JPH07120642B2 - Semiconductor device and manufacturing method thereof - Google Patents

Description

The present invention relates to a semiconductor substrate, particularly a GaAs device, in which a metallized portion is provided on the side surface of the chip for imparting mechanical strength to the device when the substrate is made extremely thin. The present invention relates to an applied semiconductor device and a manufacturing method thereof.

[Conventional technology]

FIG. 4 is a sectional view of a conventional semiconductor device of this type. In this figure, 1 is a semiconductor substrate, 2 to 4 are actual elements formed on the surface of the semiconductor substrate 1, 5 is a feeding layer required for electroplating, and 6 is a back surface formed on the back surface of the semiconductor substrate 1. A metal layer 11 serving as an electrode is a metallized portion formed on the side surface of the chip, and the metallized portion 11 is formed so as to project also on the surface of the chip.

Next, a method of manufacturing the semiconductor device of FIG. 4 will be described with reference to FIGS.

First, the actual device 2 is formed on the semiconductor substrate 1, for example, a GaAs wafer.
4 (FIG. 5 (a)), and then a GaAs wafer is subjected to a photolithography process to form a resist pattern so that a region other than a region (scribe line portion) where a chip is to be separated is covered with a resist (not shown). Then, using this resist pattern as a mask, substrate etching is performed on the GaAs wafer to form the separation groove 8. Further, the isolation groove 8 is etched to a depth equal to the desired substrate thickness. After that, the resist is removed (FIG. 5 (b)). Next, in the photolithography process, the actual element 2
Lower resist 9 so that ~ 4 is completely covered with resist 9
And the lower layer resist 9 is patterned so that the scribe line portion formed in the previous step is exposed (FIG. 5C). Next, for example, a sputtered metal film is formed on the entire surface of the GaAs wafer, and the power supply layer 5 required when performing electroplating in a later step is formed. Then, an upper layer resist 10 is formed thereon again and patterned to form a resist pattern (FIG. 5 (d)). The upper layer resist 10 is a resist that serves as a wall during electroplating. Next, by an electroplating method on the exposed portion of the power feeding layer 5,
For example, gold is grown to form the metallized portion 11 on the side surface of the chip (FIG. 5 (e)). Then, the upper and lower resists 10 and 9 and the power feeding layer 5 which are no longer needed and are used for electroplating are removed (FIG. 5 (f)). This completes the surface process.

Next, the GaAs wafer is ground to a desired thickness, and a metal layer 6, which is a back electrode, for example, a metal is formed on the entire ground surface (FIG. 5 (g)). Finally, each semiconductor device is separated along the scribe line of the separation groove 8 using, for example, a dicer, a scriber, etc. (FIG. 5 (h)).

Since each semiconductor device formed by such a method has a side surface covered with a metallized portion 11 made of gold or the like, when gripping the element with tweezers or the like, or carrying it in a case,
The mechanically brittle GaAs part is effective without cracking or cracking. A partially enlarged perspective view of the side surface of the completed chip is shown in FIG.

[Problems to be Solved by the Invention]

The conventional metallization structure on the side surface of the chip as described above has a structure in which the front surface side of the semiconductor device is also covered with the metal, that is, the metallized portion 11. In such a case, the metallized portion 11 on the side surface is too close to the electrodes of the actual elements 2 to 4 on the side surface,
A short circuit may occur during wire bonding. Further, each element is soldered when being fixed to the carrier, but the solder may reach the surface of each semiconductor device and cause a short circuit.

Further, in the manufacturing method, since the photolithography is required after a significant step is formed on the substrate surface due to the formation of the separation groove 8, the uneven resist film thickness at the step portion or the resist residue generated at the bottom of the step recess is formed. Such problems occur. further,
The photolithography process as many as twice and the resist removing process accompanied therewith are required, which causes a problem that the number of processes is significantly increased.

The present invention has been made in order to solve the above-mentioned many problems, and an object thereof is to obtain a semiconductor device in which a metallized structure on the side surface of a chip is formed only on the side surface of an element and a manufacturing method thereof. Is.

[Means for Solving the Problem] A semiconductor device according to the present invention is one in which a metallized portion is formed on a side surface of a semiconductor chip so as to be continuous with a metal layer so as not to be metallized on the surface of the semiconductor chip.

Further, in the method for manufacturing a semiconductor device of the present invention, after forming a semiconductor substrate on which a plurality of sets of actual elements are formed to a desired thickness, a resist pattern is formed on the semiconductor substrate, and the scribe pattern is used as a mask. Forming a separation groove in a portion, removing the resist pattern, forming a metal layer on the entire back surface so as to fill the separation groove, and further scribing from a scribe line of the separation groove to separate each semiconductor device. The metallized portion is formed on the side surface of the chip continuously and simultaneously with the metal layer formed on the back surface.

[Action]

In the semiconductor device according to claim (1) of the present invention, since the metallization portion is formed simultaneously with the metal layer on the back surface only on the side surface of the chip and the metallization portion is not formed on the front surface, the bonding wire at the time of wire bonding is There is no short circuit due to side surface metallization, nor does the solder used when fixing to the carrier rise to the surface and cause a short circuit.

Further, in the method for manufacturing a semiconductor device according to claim (2) of the present invention, since the method which does not require the photolithography process after the formation of the separation groove is adopted, the unevenness of the resist film pressure in the step portion and the resist It is possible to reduce problems such as residuals, simplify the process, and shorten the construction period.

〔Example〕

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

FIG. 1 is a sectional view of a semiconductor device showing an embodiment of the present invention. In FIG. 1, 1 is a semiconductor substrate, 2 to 4 are actual elements formed on the surface of the semiconductor substrate 1, 5 is a power supply layer necessary for electroplating, and 6 is a back surface formed by electroplating on the back surface of the element. A metal layer 6a to be an electrode is a metallized portion formed on the side surface of the element.

Next, a method of manufacturing the semiconductor device of FIG. 1 will be described with reference to FIGS.
(E) will be described.

First, as shown in FIG. 2 (a), a plurality of sets of actual elements 2 to 4 are formed on the semiconductor substrate 1, and then, as shown in FIG. 2 (b), the semiconductor substrate 1 is formed to a desired thickness. Then, as shown in FIG. 2 (c), photolithography is performed on the back surface of the semiconductor substrate 1 to pattern the resist 7, and the resist pattern is used as a mask to form a scribe line portion from the back side of the semiconductor substrate 1. The separation groove 8 is formed. After that, as shown in FIG. 2D, after removing the resist 7 on the back surface of the semiconductor substrate 1, a power feeding layer 5 for electroplating is formed on the entire back surface, and this power feeding layer 5 is used to form a back electrode. The metal layer 6 to be formed, for example, a metal is formed by electroplating. Finally, as shown in FIG. 2 (e), each element is separated along the scribe line of the separation groove 8 by using a dicer or a scriber, so that the metallized portion is formed on the side surface of the element.
6a is formed simultaneously with the metal layer 6 to obtain the semiconductor device of FIG.

FIG. 3 is an enlarged perspective view showing the side surface of the completed chip.

In each semiconductor device manufactured by such a method, the metallized portion 6a on the side surface and the metal layer 6 which is the back surface electrode of the semiconductor substrate 1 can be formed simultaneously, so that the number of steps can be significantly reduced. Further, since the metallized portion 6a on the side surface is formed from the back surface, the metallization does not wrap around the front surface side, and it is possible to solve the problem such as a short circuit at the time of wire bonding of the element on the front surface side unlike the conventional example. Further, since the photolithography process after the formation of the separation groove 8 with a remarkable step is not performed unlike the conventional case, the problem of the resist residue generated in the concave portion of the step is solved.

In addition, in the above embodiment, the metal layer 6 was formed by electroplating after forming the power feeding layer 5 with respect to the structure and forming method of the metallized portion 6a on the side surface and the metal layer 6 to be the back surface electrode. , Considering personality, performance, etc.
For example, even if it is omitted only for electroless plating and metal film sputtering, there is no problem, and the same effect as that of the above-mentioned embodiment can be obtained.

Further, regarding the last chip separation, the above-mentioned embodiment showed mechanical separation cutting by a scriber or a dicer, but another step is added to wet separation using a resist mask, dry etching or the like. Good.

〔The invention's effect〕

As described above, in the semiconductor device according to claim (1) of the present invention, the continuous metallized portion is formed only on the chip side surface and the back surface except the semiconductor chip front surface. A short circuit due to the rise of solder is prevented.

Further, in the method for manufacturing a semiconductor device according to claim (2) of the present invention, after forming a semiconductor substrate on which a plurality of sets of actual elements are formed to a desired thickness, a resist pattern is formed on the semiconductor substrate. Separation grooves are formed in each scribe portion using the resist pattern as a mask, and after the resist pattern is removed, the separation grooves are embedded, and at the same time, a metal layer is formed on the entire back surface and further scribed from a scribe line of the separation grooves. Since the metallized portion continuous with the metal layer formed on the back surface is formed on the side surface of the chip by separating each semiconductor device, the metallized portion on the side surface of the chip is formed at the same time as the back surface electrode and is formed on the surface of the wafer. Since it is not metallized, troubles such as resist residue generated in the concave portion having a remarkable step difference as in the conventional case are significantly reduced. In addition, since the photolithography process is not performed after the formation of the separation groove, the process can be simplified, the construction period can be shortened, and the long-term performance of the device can be stabilized and the quality and reliability can be improved.

[Brief description of drawings]

1 is a sectional view of a semiconductor device showing an embodiment of the present invention, FIG. 2 is a sectional view of a process for explaining a method of manufacturing the semiconductor device of FIG. 1, and FIG. 3 is a sectional view of FIG. FIG. 4 is a cross-sectional view of a conventional semiconductor device, FIG. 5 is a process cross-sectional view for explaining a method for manufacturing the semiconductor device of FIG. 4, and FIG. It is a partial expansion perspective view of a chip side surface part. In the figure, 1 is a semiconductor substrate, 2 to 4 are real elements, 5 is a power feeding layer, 6 is a metal layer, 6a is a metallized portion, 7 is a resist,
Reference numeral 8 is a separation groove. The same reference numerals in each drawing indicate the same or corresponding parts.

Claims (2)

[Claims] 1. A semiconductor device in which a metallized portion is formed on a side surface of a semiconductor chip in which an actual element is formed on a semiconductor substrate and a metal layer is formed on the back surface, and the metallization is continuous only on the side surface and the back surface of the chip except the surface of the semiconductor chip. A semiconductor device, wherein a portion is formed and the portion is cut by a dicer or the like. 2. A semiconductor substrate on which a plurality of sets of actual elements are formed is formed to a desired thickness, a resist pattern is formed on the semiconductor substrate, and a separation groove is formed in each scribe portion using the resist pattern as a mask. The step of, after removing the resist pattern, a step of forming a metal layer on the entire back surface at the same time as filling the separation groove, and by scribe from a scribe line of the separation groove to separate each semiconductor device, to the chip side surface, The method of manufacturing a semiconductor device according to claim 1, further comprising a step of forming a metallized portion continuous with the metal layer formed on the back surface and a step of cutting the portion with a dicer.