JPS61280660A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To reduce the electric resistance and thermal resistance of a wafer by a method wherein the wafer is once stuck on a reinforcing plate of a transparent member and thinned and then the reinforcing plate is removed to make the wafer thin sufficiently. CONSTITUTION:An element is formed in a very shallow region under the main surface of a wafer 10. Next, this wafer 10 being set on the main surface side, it is stuck on a reinforcing plate 12 formed on a transparent member, with an adhesive layer 11 interposed therebetween. It is because positioning be accurate in a subsequent scribing process that the reinforcing plate 12 is formed of the transparent member. The exposed back side of the wafer 10 is subjected to lapping or the like, and the wafer 10 is cut into a thin wafer 13. After the back surface is subjected to a prescribed back-surface processing, a back-side electrode 14 is stuck thereon. Then, the scribing process is applied to the back- side electrode 14 and the wafer 13 to form scribed grooves 15. Thereafter the adhesive layer 11 is melted away by a prescribed solvent, and thereby semiconductor devices 20 comprising respective elements are obtained.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a method for manufacturing a semiconductor device.

[Technical background of the invention]

Conventionally, a semiconductor device consisting of a high-frequency, high-output transistor has been manufactured by a process shown in FIG.
It is built. That is, first, as shown in the same figure (~
Thickness Ds3 when a predetermined element (not shown) is formed on the main surface side
A wafer 1 having a diameter of 00 to 600 μm is prepared. Next, about 150 to 350 mm of the back side of this wafer 1 is removed to form a thin 9-layer wafer 2 with a thickness Dz of 150 to 250 μm, as shown in FIG. The purpose of reducing the thickness in this way is to lower thermal resistance and electrical resistance. Next, as shown in the same figure (Q), the back electrode 3 is attached to the back side of the thinned wafer 2.Next, as shown in the same figure (O), the back electrode 3 and the wafer 2 are attached to each predetermined element. A scribe #4 is formed to divide the wafer into patterns.Then, by dividing the wafer 2 according to the scribe groove 4, the wafer 2 is divided into patterns (E)
As shown in K, a semiconductor device 5'j&
:obtain.

[Problems with background technology]

In the conventional method of obtaining a semiconductor device in this way, the limit to which the wafer 1 can be made thin is usually about 150 to 250 μm because it is limited by the subsequent scribing process and the like.

For this reason, the electrical resistance and thermal resistance could not be sufficiently reduced, and a highly reliable semiconductor device 5 could not be obtained.

Therefore, a measure has been taken to reduce the thermal resistance by increasing +L' and making the wall thickness relatively thin, but this measure has the disadvantage of increasing the size of the device.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a semiconductor device that can easily produce a semiconductor device that achieves reductions in electrical resistance and thermal resistance by making the wafer sufficiently thin.

[Summary of the invention]

The present invention provides a semiconductor device that achieves reductions in electrical resistance and thermal resistance by attaching a wafer to a reinforcing plate made of a flat transparent material to make it thinner and then removing the reinforcing plate. This is a method of manufacturing a semiconductor device that can easily obtain the following.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram showing the method of the present invention in the order of steps. First, as shown in FIG. Thickness L1300~
A 600 μm wafer J0 is prepared. The elements are usually formed in an extremely shallow region of less than 10 μm from the main surface of the wafer 10. Next, this wafer 1o is adhered onto a reinforcing plate 12 made of a transparent member via the adhesive layer 1 on the main surface side, as shown in FIG. As the reinforcing plate 12, for example, a glass plate is used. The reason why the reinforcing plate 12 is made of a transparent material is that it can strengthen the wafer JO rather than destroying it during the thinning of the wafer 10 during alignment in the subsequent scribing process (wafer dividing process) and after that. That's fine. Although not shown, the wafer 10
Predetermined electrodes and an insulating film are formed on the main surface of. As shown in the same figure (Q), wrapping or the like is performed on the exposed back side of the wafer 10 to increase the thickness of the wafer 10.
A thin wafer 13tlC of ~50 μm is cut. next,
After performing a predetermined backside treatment on the backside of the wafer 13, the same figure (
As shown in FIG. 1, the back electrode 14 is attached.

Next, as shown in the same figure (Q), the back electrode 14 and the wafer 1
3 are subjected to a scribing process to form scribe grooves 15 for dividing them into predetermined elements. After that,
Adhesive layer 11t - Dissolved with a specified solvent and
As shown, a semiconductor device 20 consisting of each element is obtained.

According to this semiconductor device manufacturing method, the wafer 10 is thinned with the reinforcing plate 12Vc attached and the scribe grooves 15 are formed, so it is possible to easily obtain the sea urchin laver 3 with a sufficiently thin wall. can. Furthermore, since the reinforcing plate 12 is made of a transparent material, the scribe grooves 15 can be easily formed with accurate alignment. As a result, since the wafer J3 is sufficiently thin, it is possible to easily obtain a semiconductor device 2θ with reduced thermal resistance and electrical resistance and improved reliability.

Incidentally, the semiconductor device 20 obtained by the method of the present invention is
(As shown in the chrysanthemum figure, the thickness L! of the wafer 13 is 10 to 50.
Although the semiconductor device 5 obtained by the conventional method has a large wall thickness D2 of 150 to 250 μm, as shown in FIG. Confirmed. Note that in FIGS. 3(A) and CB), 21 is an insulating film, and 22 is a long electrode.

〔Effect of the invention〕

As explained above, according to the method of manufacturing a semiconductor device according to the present invention, it is possible to easily obtain a semiconductor device that achieves reductions in electrical resistance and thermal resistance by making the wafer sufficiently thin.

[Brief explanation of drawings]

Figure 1 (A) to the same figure (Figure 2 is an explanatory diagram showing the method of the present invention in the order of steps, Figure 2 is an explanatory diagram showing the effects of the present invention, Figure 3 (A) to Figure (E) is an explanatory diagram showing a conventional method for manufacturing a semiconductor device in the order of steps. 1θ, 13... Wafer, 11... Adhesive layer, 12...
... Reinforcement plate, 14... Back electrode, 15... Spray 20... Semiconductor device, 21... Insulating film, 22...
electrode. Applicant's agent Patent attorney Takehiko Suzue @ 1 Figure

Claims (1)

[Claims] a step of attaching a wafer on which a predetermined element is formed to a reinforcing plate made of a transparent member via an adhesive on the main surface side; a step of removing the exposed back side of the wafer by a predetermined thickness; forming an electrode on the back surface of the wafer after removal;
A method for manufacturing a semiconductor device, comprising the steps of: dividing the electrode and the wafer into a predetermined shape; and peeling off the reinforcing plate from the divided wafer.