JP2000012490A - Manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a semiconductor device with high yield while protecting a semiconductor substrate against crack and warp. SOLUTION: A plurality of semiconductor elements 5 are formed on a semiconductor substrate 1 secured such that the surface arranged with the semiconductor elements 5 faces a supporting substrate 6. The semiconductor substrate 1 is divided for each semiconductor element 5 and the supporting substrate 6 is bonded to an expanding/contracting sheet 10. The supporting substrate 6 is divided for each semiconductor element 5 and separated from the expanding/contracting sheet 10 along with the semiconductor element 5. The semiconductor substrate 1 is formed on a package 11 and then the supporting substrate 6 is separated therefrom.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device for manufacturing a semiconductor element with a high yield and mounting it on a package.

[0002]

2. Description of the Related Art First, a conventional method for manufacturing a semiconductor device will be described with reference to FIGS.

As shown in FIG. 28, a source electrode 2 and a source electrode 2 are formed on a semiconductor substrate 1 made of GaAs and having a thickness of 600 μm.
A plurality of semiconductor elements 5 each including the gate electrode 3 and the drain electrode 4 are formed.

[0004] Next, as shown in FIG.
And a support substrate 6 made of quartz and an electron wax 7
Then, as shown in FIG. 30, the back surface of the semiconductor substrate 1 is polished until the thickness of the semiconductor substrate 1 becomes 50 μm. Thereafter, in order to improve the stability and heat dissipation of the semiconductor substrate 1 in the die bonding step performed later, as shown in FIG. Form.

Next, as shown in FIG. 32, the support substrate 6 and the electron wax 7 are separated from the semiconductor substrate 1 by a wax remover.

Next, as shown in FIG. 33, a dicing sheet 10 having elasticity is mounted on the side of the semiconductor substrate 1 on which the metal film 9 is formed. Then, the semiconductor substrate 1 and the metal film 9 are cut for each semiconductor element 5 as shown in FIG. 34 by a dicing saw (not shown), and the individual semiconductor substrates 1 formed by cutting as shown in FIG. Metal film 9
At the same time, it is peeled off from the dicing sheet 10.

[0007] Finally, as shown in FIG.
Is formed on a semiconductor package 11, and wiring between the semiconductor element 5 and the package 11 is performed by wire bonding as shown in FIG.

[0008]

However, in the conventional method of manufacturing a semiconductor device, the steps from the step of separating the support substrate and the electron wax from the semiconductor substrate by the wax remover to the step of forming the semiconductor substrate on the package are performed. In this case, there is no structure for supporting the thin semiconductor substrate, and the semiconductor substrate may be cracked or warped, thereby significantly reducing the yield of the semiconductor device.

The reason why the semiconductor substrate is formed thin is to efficiently release heat generated in the semiconductor element.
When the thickness of the semiconductor substrate is 150 μm or less, cracks and warpage are particularly likely to occur.

An object of the present invention is to provide a method for manufacturing a semiconductor device which is less likely to crack or warp in a semiconductor substrate and has a good yield.

[0011]

According to the present invention, there is provided a method for manufacturing a semiconductor device, comprising: forming a plurality of semiconductor elements on a semiconductor substrate;
A surface of the semiconductor substrate on which the semiconductor element is formed,
The semiconductor substrate and the support substrate are fixed so that the support substrate faces each other, the semiconductor substrate is divided for each of the semiconductor elements, the support substrate is fixed to an elastic sheet, and the support substrate is fixed to the semiconductor substrate. The support substrate is divided for each element, the divided support substrate is separated from the stretchable sheet together with the semiconductor element, the semiconductor substrate is formed on a package, and then the support substrate is separated from the semiconductor substrate.

According to the present invention, since the semiconductor substrate is supported by the support substrate until the step of forming on the package, cracks and warpages hardly occur.

[0013]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 27.

(First Embodiment) FIGS. 1 to 12 are views showing a manufacturing process of a semiconductor device according to a first embodiment of the present invention. First, as shown in FIG.
A plurality of semiconductor elements 5 each having a source electrode 2, a gate electrode 3, and a drain electrode 4 are formed on a semiconductor substrate 1 made of GaAs having a thickness of 600 μm.

Next, as shown in FIG. 2, the semiconductor substrate 1 and a support substrate 6 made of quartz are bonded by electron wax 7 until the thickness of the semiconductor substrate 1 becomes 50 μm as shown in FIG. Then, the back surface of the semiconductor substrate 1 is polished.
Then, as shown in FIG. 4, a photoresist 8 is formed on a portion corresponding to each semiconductor element 5 on the back surface of the semiconductor substrate 1 and dry etching is performed using the photoresist 8 as a mask, as shown in FIG. Then, a part of the semiconductor substrate 1 is removed so that the semiconductor substrate 1 is divided for each semiconductor element 5. Then, as shown in FIG. 6, a metal film 9 made of Cr, Au, or the like is formed on the semiconductor substrate 1 by vapor deposition in order to improve the adhesiveness of the semiconductor substrate 1 in a die bonding step performed later.

Next, as shown in FIGS. 7 and 8, the support substrate 6 is bonded to a dicing sheet 10 having elasticity, and the support substrate 6 is divided into semiconductor elements 5 by a dicing saw (not shown). .

As shown in FIGS. 9 and 10, the support substrate 6 is peeled off from the dicing sheet 10 together with the semiconductor substrate 1 and the semiconductor element 5, and the semiconductor substrate 1 is placed on a semiconductor package 11, and the support substrate 6 is removed. Die bond so that it is on the upper side. At this time, if a low melting metal such as AuSn foil or solder is formed between the package 11 and the metal film 9, the adhesion between the package 11 and the metal film 9 is improved. Thereafter, as shown in FIG. 11, the support substrate 6 and the electron wax 7 are separated from the semiconductor substrate 1 by a wax remover.

Finally, as shown in FIG. 12, wiring between the semiconductor element 5 and the package 11 is performed by wire bonding.

In the method of manufacturing a semiconductor device according to the first embodiment of the present invention, the semiconductor substrate 1 is fixed to the support substrate 6 until the semiconductor substrate 1 is fixed to the package 11, so that the semiconductor substrate 1 is cracked or warped. Is less likely to occur. For this reason, the yield of semiconductor devices is dramatically improved.

In the present invention, the semiconductor substrate 1 is made of Si, I
The same effect can be obtained by using a material other than GaAs, such as nP or sapphire.

In this embodiment, a field effect transistor having a source electrode 2, a gate electrode 3, and a drain electrode 4 is used as the semiconductor element 5, but a bipolar transistor, a capacitor, or the like is used. Can obtain the same effect.

Similarly, the same effect can be obtained by using a material such as glass or Si in addition to quartz as the material of the support substrate 6.

(Embodiment 2) FIG. 13 to FIG.
FIG. 5 is a diagram illustrating a process relating to the method for manufacturing the semiconductor device in the first embodiment of the present invention. First, as shown in FIG. 13, a source electrode 2, a gate electrode 3,
A plurality of semiconductor elements 5 each having the drain electrode 4 formed thereon are formed.

Next, as shown in FIG.
And a support substrate 6 made of quartz and an electron wax 7
Then, as shown in FIG. 15, the back surface of the semiconductor substrate 1 is polished until the thickness becomes 50 μm. And FIG.
As shown in FIG. 6, a metal film 9 is formed by evaporating titanium having a thickness of 500 angstroms and gold having a thickness of 2000 angstroms on the semiconductor substrate 1.

Next, as shown in FIG. 17, a photoresist 8 is formed on the surface of the metal film 9 except for the portion corresponding to the semiconductor element 5, and as shown in FIG.
A thick film plating 12 made of gold having a thickness of 20 μm to 30 μm is formed in a region other than the portion where the photoresist 8 is formed by a plating method, and the photoresist 8 is removed with acetone. The metal film 9 serves as seed metal for the thick film plating 12.
Further, the thick film plating 12 functions as a heat sink of the semiconductor element 5.

Next, as shown in FIG.
The metal film 9 is removed by KI etching using the mask 2 as a mask, and the exposed portion of the semiconductor substrate 1 is removed as shown in FIG.
As shown in FIG.

Next, as shown in FIGS. 21 and 22,
The support substrate 6 is adhered to a dicing sheet 10 having elasticity, and the support substrate 6 is bonded to the semiconductor element 5 using a dicing saw.
Divide each time.

Further, as shown in FIGS. 23 and 24, the supporting substrate 6 is peeled off from the dicing sheet 10 together with the semiconductor substrate 1 and the semiconductor element 5, and the semiconductor substrate 1 is placed on a semiconductor package 11, and the supporting substrate 6 Die bond so that it is on the upper side. At this time, if a low melting metal such as AuSn foil or solder is formed between the package 11 and the metal film 9, the adhesion between the package 11 and the metal film 9 is improved. Thereafter, as shown in FIG. 25, the support substrate 6 and the electron wax 7 are separated from the semiconductor substrate 1 by a wax remover.

Finally, as shown in FIG. 26, wiring between the semiconductor element 5 and the package 11 is performed by wire bonding.

In the second embodiment, since the thick film plating 12 acting as a heat sink is formed on the semiconductor substrate 1, the heat dissipation of the semiconductor device is improved.

As another method of manufacturing a semiconductor device according to the second embodiment, a method of manufacturing a semiconductor device in which a via hole is formed in a substrate will be described.

In the step shown in FIG. 15, if a via hole reaching the source electrode 2 is provided in the semiconductor substrate 1, the completed semiconductor device has the structure shown in FIG. At this time, since the source electrode 2 is directly grounded through the semiconductor substrate 1, it is not necessary to perform wire bonding to the source electrode 2, and therefore, a semiconductor device with small parasitic inductance can be obtained.

[0033]

As described above, in the method of manufacturing a semiconductor device according to the present invention, the semiconductor substrate is supported by the support substrate until the semiconductor substrate is formed on the package. Cracks and warpage hardly occur. Therefore, the yield of the semiconductor device is significantly improved.

[Brief description of the drawings]

FIG. 1 is a view showing a manufacturing process of a semiconductor device according to a first embodiment of the present invention;

FIG. 2 is a view showing a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 3 is a diagram showing a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 4 is a view showing a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 5 is a diagram showing a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 6 is a diagram illustrating a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 7 is a view showing a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 8 is a diagram showing a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 9 is a view showing a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 10 is a diagram showing a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 11 is a diagram showing a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 12 is a view showing a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 13 is a diagram illustrating a manufacturing process of the semiconductor device according to the second embodiment of the present invention;

FIG. 14 is a view showing a manufacturing process of the semiconductor device according to the second embodiment of the present invention;

FIG. 15 is a diagram illustrating a manufacturing process of the semiconductor device according to the second embodiment of the present invention;

FIG. 16 is a diagram illustrating a manufacturing process of the semiconductor device according to the second embodiment of the present invention;

FIG. 17 is a diagram illustrating a manufacturing process of the semiconductor device according to the second embodiment of the present invention;

FIG. 18 is a diagram illustrating a manufacturing process of the semiconductor device according to the second embodiment of the present invention;

FIG. 19 is a diagram showing a manufacturing process of the semiconductor device according to the second embodiment of the present invention;

FIG. 20 is a diagram showing a manufacturing process of the semiconductor device according to the second embodiment of the present invention;

FIG. 21 is a diagram illustrating a manufacturing process of the semiconductor device according to the second embodiment of the present invention;

FIG. 22 is a diagram illustrating a manufacturing process of the semiconductor device according to the second embodiment of the present invention;

FIG. 23 is a diagram illustrating a manufacturing process of the semiconductor device according to the second embodiment of the present invention;

FIG. 24 is a diagram illustrating a manufacturing process of the semiconductor device according to the second embodiment of the present invention;

FIG. 25 is a diagram showing a manufacturing step of the semiconductor device according to the second embodiment of the present invention;

FIG. 26 is a diagram illustrating a manufacturing process of the semiconductor device according to the second embodiment of the present invention;

FIG. 27 is a view showing a manufacturing process of another semiconductor device according to the second embodiment of the present invention;

FIG. 28 is a diagram showing a manufacturing process of a conventional semiconductor device.

FIG. 29 is a view showing a manufacturing process of a conventional semiconductor device.

FIG. 30 is a view showing a manufacturing process of a conventional semiconductor device.

FIG. 31 is a view showing a manufacturing process of a conventional semiconductor device.

FIG. 32 is a view showing a manufacturing process of a conventional semiconductor device.

FIG. 33 is a diagram showing a manufacturing process of a conventional semiconductor device.

FIG. 34 is a diagram showing a manufacturing process of a conventional semiconductor device.

FIG. 35 is a view showing a manufacturing process of a conventional semiconductor device.

FIG. 36 is a view showing a manufacturing process of a conventional semiconductor device.

FIG. 37 is a diagram showing a manufacturing process of a conventional semiconductor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor substrate 2 Source electrode 3 Gate electrode 4 Drain electrode 5 Semiconductor element 6 Support substrate 7 Electron wax 8 Photoresist 9 Metal film 10 Dicing sheet 11 Package 12 Thick film plating

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Claims (3)

[Claims] 1. A semiconductor device comprising: a plurality of semiconductor elements formed on a semiconductor substrate; and a semiconductor substrate and the support substrate fixed to each other such that a surface of the semiconductor substrate on which the semiconductor elements are formed faces a support substrate. Then, the semiconductor substrate is divided for each of the semiconductor elements, the support substrate is fixed to an elastic sheet,
The support substrate is divided for each of the semiconductor elements, the divided support substrate is separated from the stretchable sheet together with the semiconductor elements, the semiconductor substrate is formed on a package, and then the support substrate is separated from the semiconductor substrate. A method for manufacturing a semiconductor device, comprising: separating a semiconductor device; 2. The method according to claim 1, further comprising a step of forming a metal film on the semiconductor substrate. 3. The method according to claim 1, further comprising a step of forming a via hole in the semiconductor substrate.