JPS61187247A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To increase the yield in manufacturing the titled device, make it easy to discriminate whether products are defective and moreover make the automatic peeling process possible, by fixing all of the defective pellets whose external shape is not square and the pellets having high probability being defective in spite of having square shape on the adhesion sheet of the wafer with resin. CONSTITUTION:Pellets 7', 7',... on the peripheral part of the wafer ring 10 are coated with as fixing material, humidifying type vulcanized silicon rubber 17 as sealing resin. To peel-off the pellets 7, 7 by employing such a wafer ring 10, the wafer ring 10 is at first inverted, and placed on the solvent storing tank 19 which stores the solvent 18 to dissolve the adhesive agent. While applying pressure on the surface of the adhesive sheet whereon wafer is not in contact, that is, the upper surface thereof by using squeegee 20, the sheet travels and releases only the pellets 7, 7,... placed on the central part, which drop into the solvent 18. Accordingly, on the adhesion sheet 11 of the wafer ring 10, the defective pellets 7', 7',... whose external shape is not normal square remain.

Description

[Detailed Description of the Invention]-1 The present invention relates to a method for manufacturing a semiconductor device, and in detail,
The present invention relates to a method of dividing a wafer on which semiconductor elements are formed into pellets using an adhesive sheet, and then separating good and defective pellets.

In the production of semiconductor devices, in order to obtain pellets, as is well known, a large number of elements are formed on a wafer through processes such as thermal diffusion, ion implantation, and etching, and the elements are then transferred to the wafer. The properties of the pellets are checked in their original state, and then they are finely divided into individual pellets. In this case, the rate of defective pellets is overwhelmingly high at the outer periphery of the wafer. The reason for this is explained with reference to FIG. 6. The reason for this is that crystal defects are concentrated on the outer peripheral edge of the wafer 1 when a single crystal ingot is manufactured before slicing the wafer 1.
and lot line 2, 2. ...and 3,3. . . . Elements 4, 4 . . . . Among them, the outer peripheral edge portion 4' is not necessarily a perfect square and inevitably causes element pattern defects. Elements 4' and 4'' that were found to be defective as a result of the characteristic check are marked with defective markings, and are further marked with wax marks as shown in FIG.
After being pasted onto a substrate 6 such as a glass plate, the pellets 7.7. are diced into individual pellets 7.7. ...
Completely cut each time.

Then, as shown in FIG. 9, the wafer 1 after dicing is placed and held in a trichlene storage tank 9 with a solvent 8 for melting the wax 5, for example, for avinisine wax, while the wafer 1 is still attached to the substrate. melt the wax 5 and separate the pellets 7.7.7'.

7', . . . are peeled off from the substrate and also cleaned.

ro (yo ′ o JL By the way,
Individual pellets from wafer 1 on substrate 6) 7,7.7
', 7', . . ., good pellets 7.7. ...and defective pellet 7Z71
．． ... remain mixed together, unfortunately.

Therefore, it is necessary to sort out whether the pellets are good or bad, but since the pellets (7, 7, 7°, 7゛, etc.) are minute, it is difficult to determine whether there are defective markings or whether they are perfectly square. there were.

This invention was proposed to solve the problems mentioned in -.

r, -ta no - - ° □This invention has an edge line of -JL, and improves the work of determining the quality of pellets by adopting the following means. In other words, the present invention involves bonding a wafer on which a large number of semiconductor devices are formed to a flexible adhesive sort and stretching the adhesive sheet by scribing, or alternatively, completely canting the wafer to finely separate the wafer into individual pellets. After dividing, a resin for fixing defective pellets is applied to the outer edge of the wafer.
2) From the back side of the adhesive sheet to which the wafer is not bonded, the adhesive sheet is pressed and squeezed using a pressing jig or the like to separate the pellets in the center of the wafer from the pellets in the outer periphery.

In other words, the present invention employs a method in which pellets at the periphery of the wafer that are probabilistically defective are divided into pieces, regarded as defective, and removed.

1. In this invention, all defective pellets whose outer shape is not rectangular, as well as pellets with a high probability of having defective characteristics even if they are rectangular, are fixed with resin to the wafer adhesive sort, so they are not pressed or squeezed. The pellets obtained by this process have a significantly increased manufacturing yield and are easier to sort out. Moreover, in this invention, the pellets that are removed while being fixed to the adhesive sheet with resin can be left in the same arrangement as the wafer, which can be useful for analyzing characteristic defects.

Figure 1 shows pellets in a pellet wafer peeling process for explaining one embodiment of the present invention.

FIG. 2 is a schematic cross-sectional conceptual diagram of a peeling device. First, the IO is a wafer ring to which the adhesive sheet 11 to which the wafer 1 is attached is fixed, and through the following process, pellets 7.7.7'
, 7', ... are bound. That is, first, as shown in FIG. 2, a visible adhesive sheet H1 made of polyvinyl chloride with an adhesive layer provided on its upper surface is prepared, a wafer 1 is pasted and fixed, and 1 scribe groove + 2. 1
2. ...and +3.13. . . . to produce a wafer attachment body 14 provided with pellet sections. Next, as shown in FIG. 3, the outer edge 11'' of the adhesive sheath H1 is hung on one end of the cane body 15 which is open at both ends, and while being loosened with the elastic ring-shaped body 16, Lower it to the state shown in Figure 4. Then, the adhesive sheet 11 is stretched radially, and the wafer 1 is formed into pellets 7.7.7', 7'.
The brakes are applied to...

As shown in FIG. 5, the wafer ring 10 thus obtained has pellets 7'', 7', . . . on its outer periphery.
For example, a humidified vulcanized silicone rubber 17 is applied as a fixing resin.

Now, 10 wafer rings obtained as in
To peel off the pellets 7.7 using the wafer ring 10, as shown in FIG. 1, the wafer ring 10 is inverted and placed on a solvent reservoir 19 containing a solvent 18 for dissolving the adhesive.

Then, by moving and handling the wafer non-adhesive surface, that is, the upper surface, of the adhesive sheet N+ while keeping it pressed with the squeegee 20, the central pellet 7.7. ... is peeled off and dropped into the solvent 18. Therefore, the adhesive sheet N+ of the wafer ring 10 contains defective pellets 7", 7' which are fixed to the resin I7 and are not in a regular square shape.
,... are left behind.

Incidentally, the subsequent step of character quality selection and subsequent steps are the same as before, and therefore will not be described.

In the second embodiment, the wafer is divided into pellets after being scribed and stretched on the adhesive sheet, but the present invention is limited to this case. It may also be cut.

According to this invention, pellets that are obviously defective are left on the wafer ring and removed, which improves the manufacturing yield and makes it easier to sort out the quality of the pellets. Automatic peeling work is also possible. Further, in the present invention, a wafer ring to which a defective pellet is stuck can be sampled during manufacturing, which is useful for failure analysis, and thus contributes to reliability.

[Brief explanation of drawings]

FIG. 1 shows a Pelle 7 for explaining one embodiment of the present invention.
) Schematic cross-sectional conceptual diagram of the peeling device, Figure 2 is a perspective view of the wafer-attached body, Figures 3 and 4 are cross-sectional views of the wafer ring, and Figure 5 is a perspective view of the resin-coated wafer ring. It is a diagram. FIG. 6 is a plan view of a general semiconductor wafer,
FIG. 7 and FIG. 8 are cross-sectional views of a conventional wafer-attached body;
FIG. 9 is a cross-sectional view of the solvent reservoir for dissolving the adhesive. ■...Wafer, 4...Element, 7.7'...Pellet, IO...Wafer ring, 11...Adhesive sheet, 17...Resin, 20...Squeegee. Fig. 3 Arrow - tension >7" (-7 and N >7") 4th Fl!
Fig. 5 Pak-san-painted wind-finishing habit ha l)>7”2
・ ゛ ・ 4・ 4′ /” ゛ 2 4p Figure 6■

Claims (1)

[Claims] A wafer on which a large number of semiconductor devices have been formed is adhered to a flexible adhesive sheet, and the adhesive sheet is stretched by scribing.The wafer is completely cut and divided into individual pellets, and then a The resin is applied to the outer peripheral edge of the wafer, and the pellets at the center of the wafer and the pellets at the outer peripheral edge are separated by pressing and squeezing with a pressing jig or the like from the back side of the adhesive sheet where the wafer is not bonded. A method for manufacturing a semiconductor device, characterized in that: