JP2830633B2 - Method for manufacturing semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a semiconductor device having a plated heat sink structure (hereinafter, referred to as a PHS structure).

[0002]

2. Description of the Related Art In general, a method of manufacturing a semiconductor device having a PHS structure is as follows. After an element is formed on the surface of a semiconductor substrate, the back surface of the semiconductor substrate is subjected to mechanical polishing and chemical erosion to a predetermined thickness as shown in FIG. Scraping, selectively on the back side of the semiconductor substrate at the position facing each surface element,
A thermally conductive metal having a thickness to be PHS is grown by vapor deposition or plating to form a back electrode, and is separated into semiconductor elements by chemical erosion or mechanical cutting.

However, after the surface element of the semiconductor substrate is formed, the semiconductor substrate is shaved to a thickness of about 20 to 40 μm. If the semiconductor substrate alone is used, the semiconductor substrate is warped and the crystal is distorted, and the semiconductor substrate is easily broken. Before the semiconductor substrate 1a is subjected to mechanical polishing and chemical erosion, the element surface side of the semiconductor substrate 1a is usually attached to the support plate 2 as shown in FIG. The semiconductor substrate 1a is prevented from warping or cracking by performing the subsequent steps.

[0004] The bonding material 3a used here is:
Mechanical strength and chemical resistance between the semiconductor substrate 1a and the support plate 2;
In consideration of heat resistance, wax or a negative resist is used, and the thickness is usually about 5 to 30 μm.

After the back electrode is formed and separated into individual elements, the semiconductor element 1b attached to the support plate 2 needs to be peeled off and washed, as shown in FIG.
The semiconductor element 1b attached to the support plate 2 is immersed in a treatment liquid 6 in which the adhesive 3a is dissolved, the adhesive 3a is dissolved, and the semiconductor element 1b is separated from the support plate 2 to remove the semiconductor element 1b. Is received by a basket-shaped jig 8 made of a wire mesh having an opening smaller than that of the semiconductor element 1b, and the semiconductor element 1b is further cleaned. The processing liquid 6b used here uses a plurality of tanks which are usually of a different solvent type so that the adhesive material 3a is easily dissolved.

At this time, in order to promote peeling and cleaning, the semiconductor element 1b affixed to the support plate 2 and the semiconductor element 1b received by the cage jig 5 in the processing liquid swing or move. , Ultrasonic waves, and the like.

The semiconductor element 1b, which has been peeled and washed, is dried and mounted, so that the semiconductor elements 1b are aligned one by one on the tray, one by one, with the front and back sides checked.

[0008]

In such a conventional method of manufacturing a semiconductor device, when the process is to be considered, the semiconductor elements which are put into the basket-shaped jig 8 in a face-to-face manner and in a superposed state are considered. It is very difficult to recognize 1b and pick up and align the individual.

When the semiconductor element 1b is peeled off and washed,
And the semiconductor elements 1b do not overlap each other,
The dimension (t dimension in FIG. 3B) between the surface of the support plate 2 on the side of the bonding material 3a and the bottom wire mesh of the cage jig 5 is set to be not more than twice the thickness of the semiconductor element 1b. By holding the support plate, inversion and overlapping of the semiconductor element 1b can be eliminated, and automation can be easily performed. However, the semiconductor element 1b has a thickness of 40 to 10 even when the back electrode is formed.
It is very thin, 0 μm, and the dimension of the support plate 2 and the bottom wire mesh of the cage jig 8, the t dimension, must be very narrow, 80 to 200 μm. In the vicinity of the above, the replacement of the processing liquid 6b is poor, and the adhesive 3 and the processing liquid 6b remain on the semiconductor element 1b and remain dry even if the cleaning time and the number of times of cleaning are increased, so that stains, appearance defects, and bonding defects may occur. Occur.

Further, in order to improve the replacement of the liquid at the time of cleaning by the above-mentioned method, when the semiconductor element 1b is peeled off from the support plate 2, the support plate 2 is removed, and a cage jig is used instead of the support plate 2. 8 can maintain the dimension t with the bottom wire mesh on the entire surface.
If cleaning is performed by covering with a wire mesh or the like having an opening smaller than b, the replacement of the liquid is improved, and the cleaning effect is improved.
It is considered that the remaining of the processing liquid 6b disappears. However, when the semiconductor element 1b is separated from the support plate 2 and the support plate 2 is removed, the size of the semiconductor element 1b is very small (depending on the product, 0.5 to 1.0 ^W ×
About 0.5~1.5 ^D × 0.04~0.1 ^t mm) In addition,
Since the semiconductor element 1b and the support plate 2 are wet with the processing liquid 6b, the semiconductor element 1b cannot be removed from the support plate 2. Also,
Once the semiconductor element 1b is peeled and washed, it is dried,
If the support plate 2 is removed, the entire surface is covered with a wire mesh, and re-cleaning is performed, the semiconductor element 1b can be removed without sticking to the semiconductor substrate 2. However, stains on the semiconductor element 1 once are cleaned again. There were problems such as difficulties in taking it.

An object of the present invention is to provide a method of manufacturing a semiconductor device capable of preventing a semiconductor element having a PSH structure from a support plate from overlapping and inverting the semiconductor element from a support plate and maintaining a sufficient cleaning effect. Is to do.

[0012]

The feature of the present invention is one principal aspect.
One main surface of a semiconductor substrate on which a plurality of semiconductor elements are formed
Material that can be selectively peeled off via the material
A step of attaching a support plate, and attaching the support plate.
Polishing or eroding the back surface of the semiconductor substrate
A step of thinning a semiconductor substrate, and a step corresponding to the semiconductor element.
Forming a back electrode, and attaching the back electrode to the support plate.
Each of the semiconductors in a state where the
Cutting and separating into a body element, and selectively peelable
Removing the support plate from the adhesive material,
A plate having a small hole as the material for attaching the semiconductor element.
Clean the semiconductor element by immersing it in a processing solution
And a method for manufacturing a semiconductor device.
You . Also , the removing step is capable of selectively peeling.
It is a process of melting and removing the paste with heat, or
Melts the selectively peelable adhesive material with a chemical solution
It is desirable that this is a removal step .

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view for explaining an embodiment of the present invention.

FIG. 1A shows a state where the semiconductor substrate 1a is attached to a support plate 2 in order to cut the semiconductor substrate 1a thinly. Adhesive material 3a on the side of semiconductor substrate 1a here is a negative resist with strong adhesion, adhesive material 3b that can be selectively peeled off on support plate 2, here a wax that can be selectively peeled off from the negative resist by heat The semiconductor substrate 1a
And the support plate 2 are pasted with a two-layer pasting material. The thickness of each adhesive layer is 5 to 3
It is about 0 μm.

Semiconductor substrate 1 attached by the above method
In FIG. 4A, the semiconductor substrate 1a is cut into a predetermined thickness as shown in the flow chart of FIG. 4, a back electrode is formed, and each element is separated while being attached to a support plate. Is separated from the support plate 2 and washed.

Here, as shown in FIG. 1 (b), first, the support plate 2 is set to a predetermined temperature at which the wax is melted by using a hot plate or the like to selectively attach the semiconductor element 1b. However, it can be easily peeled from the support plate 2 in a film state while being held by the negative resist in the other bonding material 3a. The semiconductor element 1b in the film state has many openings smaller than the dimensions of the semiconductor element 1b as shown in FIG. 1 (c). A thin plate that can maintain a dimension of not less than twice the thickness and not less than the thickness is held so as to be sandwiched, and is treated with a treatment liquid in which the adhesive material 3a is dissolved.
And the cleaning effect is improved, and the semiconductor element 1b can be cleaned without inversion and without overlapping, and automation between processes can be easily performed. Further, here, a conventional rocking or ultrasonic wave may be applied to promote the replacement of the liquid.

FIG. 2 is a sectional view showing a second embodiment.

FIG. 2A shows a state in which the semiconductor substrate 1a is attached to the support plate 2 as in the first embodiment. An adhesive material 3a, here a negative resist having strong adhesion, is used on the semiconductor substrate 1a side, and a selectable adhesive material 3b is a material which can be selectively peeled off from the negative resist by using a solvent. Here, methyl ethyl ketone ( (Hereinafter referred to as MEK), a negative resist and a positive resist that can be selectively peeled off are used. It is known that a positive resist is generally easily dissolved in MEK.
It is known that EK does not dissolve. However, since the positive resist has good adhesive strength to the semiconductor substrate 1a or the support plate 2 (for example, a glass plate), it is used in a state where the positive resist is sandwiched between negative resists as reinforcement.

FIG. 2B is a view showing the separation from the support plate 2 after each semiconductor element 1b is separated. As shown in the figure, the selective bonding material 3b can be easily dissolved only in the positive resist in the processing liquid 6a, here, in the MEK, and the semiconductor element 1b can be easily dissolved in the bonding material 3a, here, in the negative system. It can be easily peeled off from the support plate 2 in a film state while being held by the resist. The semiconductor element 1b in the film state can be washed as in the first embodiment. Further, in the case of this embodiment, the semiconductor element in a film state with the negative resist can be washed by dry treatment (O ₂ plasma treatment) or the like, and the semiconductor element 1b can be cleaned without using a special jig. Can be washed without inversion and without overlapping each other.

The peeling by the method of the present invention and the conventional method,
Table 1 shows the results of measurement of the defect rate due to the cleaning process and the rate of no overlap and inversion of semiconductor elements (alignment rate).

[0022]

As is clear from Table 1, when the defect rate is reduced to 1% or less by the conventional method (1), the alignment rate becomes 5% or less. When the alignment rate is 100% as in the conventional method (2), the alignment rate becomes 100%. The defective rate was 90% or more, and a favorable result was not obtained. On the other hand, in the method of the present invention, the defective rate was 1% or less, and the alignment rate was 100%.

[0024]

As described above, according to the present invention, the semiconductor element is previously peeled off from the support material in the form of a film without peeling off and washing without overlapping or reversing by peeling off the semiconductor element from the support plate. Is possible,
The defect rate due to the peeling and cleaning steps can be reduced to 1% or less.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a process according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view for explaining another embodiment of the present invention in each step.

FIG. 3 is a cross-sectional view for explaining a conventional method for manufacturing a semiconductor device.

FIG. 4 is a diagram showing a flow of steps of a conventional semiconductor device manufacturing method.

[Explanation of symbols]

 Reference Signs List 1a Semiconductor substrate 1b Semiconductor element 2 Support plate 3a Adhesive material 3b Selective adhesive material 4 Holding jig 5a, 5b Processing bath 6a, 6b Processing liquid 7 Hot plate 8 Basket jig

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁶ , DB name) H01L 21/301 H01L 23/40

Claims (3)

(57) [Claims] 1. A plurality of semiconductor elements are formed on one main surface.
Selectively peel off the one main surface of the semiconductor substrate via an adhesive.
A step of attaching the support plate with a detachable attaching material,
Polishing the back surface of the semiconductor substrate attached to the support plate;
Polishing or eroding to thin the semiconductor substrate;
Forming a back electrode corresponding to the semiconductor element;
The semiconductor substrate attached to the support plate is attached.
Cutting and separating each of the semiconductor elements in the separated state;
The support plate is separated from the adhesive material that can be selectively peeled off
Removing step and attaching the semiconductor element
Insert the material between the plates with small holes and immerse in the treatment liquid
A method of manufacturing a semiconductor device, comprising: cleaning a semiconductor element . 2. The method according to claim 1 , wherein said removing step is capable of selectively peeling.
2. The method for manufacturing a semiconductor device according to claim 1, further comprising the step of melting and removing the functional adhesive material by heat . 3. The method according to claim 1, wherein the removing step includes the step of selectively peeling.
A method according to claim 1 Symbol mounting, characterized in that the ability of pasted material is a step of removing dissolved in the chemical solution.