JPH0817164B2 - Semiconductor device manufacturing equipment - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device manufacturing apparatus, and more particularly to a rotary drying apparatus for semiconductor wafers.

2. Description of the Related Art In recent years, with the increasing integration and miniaturization of semiconductor integrated circuits, it is an important issue to reduce the adhesion of particles in the submicron class even in a semiconductor device manufacturing apparatus used for manufacturing these semiconductor devices. Has become. Above all, the semiconductor wafer cleaning technique is a very important technique for removing particles and impurities attached during the manufacture of semiconductor devices. In these cleaning devices, a rotary dryer is often used to dry the semiconductor wafer after the final cleaning. The rotary dryer is a device that spins a semiconductor wafer at high speed and scatters the liquid on the semiconductor wafer by centrifugal force to dehydrate the semiconductor wafer.

FIG. 1b shows a sectional view of the rotary dryer. A wafer cassette holder 1 is held by a supporting arm 6 around a rotating shaft 8 connected to a rotating mechanism 9. Inside the wafer cassette holder 1, a plurality of semiconductor wafers 3 are stacked and non-conductive and chemical resistant. The wafer cassette 2 is held. The wafer cassette 2 is manually or automatically transferred from the cleaning device and set in the wafer cassette holder 1. The wafer cassette holder 1 holding the semiconductor wafer 3 and the wafer cassette 2 performs an orbital rotation motion around the rotation shaft 8 to perform dehydration. FIG. 2 is a sectional view of the portion of the wafer cassette holder 1 shown in FIG. 1b taken along the line AA '. The wafer cassette holder 1 is held on both sides by support arms, and the semiconductor wafer 3 is non-conductive,
It is loaded on a chemically resistant wafer cassette 2. Therefore, the semiconductor wafer 3 is not in electrical and mechanical contact with the wafer cassette holder 1.

Problems to be Solved by the Invention The wafer cassette holder described in the conventional example has a structure in which it is mechanically non-contact with the semiconductor wafer by the non-conductive wafer cassette. In the rotary dryer, a large amount of static electricity is generated due to friction between the wafer and the surrounding atmosphere as the wafer rotates at high speed. Since the semiconductor wafer is not electrically and mechanically in contact with the wafer cassette holder, these static electricity have no escape and are accumulated between the wafers in the form of a so-called capacitor. The accumulated charges are not discharged because there is no escape area for the charges even after the completion of the rotation drying. As described above, when electric charges are accumulated between the wafers, the particles floating in the atmosphere due to static electricity are easily attached to the wafer, and the particles once attached are hard to be removed due to the static electricity. Furthermore, when these charged wafers are mounted on other devices, discharge occurs between the wafers and between other metal substances and the wafer, resulting in electrostatic breakdown of the gate oxide film of MOS transistors and capacitive insulating film of DRAM, etc. This lowers the manufacturing yield of the device.

The present invention is for solving the above-mentioned static electricity generated during the spin-drying, which is caused by the accumulation of particles between the wafers and the electrostatic breakdown of the semiconductor element due to the static electricity accumulated between the wafers. The present invention realizes a semiconductor device manufacturing apparatus having a structure for preventing accumulation of static electricity between wafers without significantly changing the structure of the rotary dryer.

Means for Solving the Problems A semiconductor device manufacturing apparatus according to the present invention includes a non-conductive and chemical-resistant wafer cassette for loading a semiconductor wafer,
It holds the wafer cassette and has a cassette holder having electric conductivity and chemical resistance while revolving around a rotating shaft that rotates the semiconductor wafer, and rotating the semiconductor wafer to centrifuge it. The wafer cassette holder is provided with a contact with a slewing formed of stainless steel 316 in which the semiconductor wafer mechanically contacts the cassette holder while the liquid adhering to the semiconductor wafer is dried by force. Is electrically grounded.

Action According to the rotary dryer of this structure, the static electricity generated by the friction between the wafer and the atmosphere during rotary drying tends to accumulate between the wafers because the wafer cassette is non-conductive, but the semiconductor wafer becomes a conductive wafer cassette holder. Because of the mechanical contact, the static electricity that tried to accumulate between the wafers flows to the wafer cassette holder, and since this wafer cassette holder is electrically grounded, these charges flow to the ground and between the semiconductor wafers. No charge is stored. Therefore, the adhesion of particles to the wafer due to static electricity can be minimized, and the semiconductor device built on the wafer is not electrostatically destroyed.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the sectional view shown in FIG.

FIG. 1a shows in detail the portion of the wafer cassette holder of the rotary dryer shown in FIG. 1b. In FIG. 1A, the wafer cassette holder 1 is held by the support arm 6 made of stainless steel 316. The contactor 4 is grounded via a spring 5 to the bottom of the wafer cassette holder. All of these materials are made of stainless steel 316 and have electrical conductivity and chemical resistance. In addition, these parts are the support arm 6
Grounded through. The semiconductor wafer 3 is loaded on a wafer cassette 2 made of Teflon, and the wafer cassette is set in the wafer cassette holder 1 manually or automatically from a cleaning device. At this time, the semiconductor wafer slightly contacts the contactor 4 at the bottom of the cassette. After setting the wafer cassette, the wafer cassette holder revolves around the axis of rotation shown in FIG. 1b. At this time, the wafer is strongly attached to the contactor 4 while being dehydrated by centrifugal force. However, since the contactor 4 is held by the spring 5, it is possible to absorb the shock generated by the contact between the wafer 3 and the contactor 4.
With these structures, the static electricity generated during the rotary drying is conducted from the semiconductor wafer 3 to the ground 7 through the contact 4, the spring 5, the wafer cassette holder 1 and the support arm 6. For this reason, static electricity does not accumulate between the wafers, and it is possible to perform dehydration in the rotary drying device without adhering particles due to static electricity or causing electrostatic damage to the semiconductor device due to discharge.

EFFECTS OF THE INVENTION As described above, the semiconductor device manufacturing apparatus according to the present invention can spin dry the semiconductor wafer without accumulating static electricity between the wafers, and the wafer due to adhesion of particles to the wafer or electrostatic breakdown due to static electricity. Dehydration without lowering the yield of the semiconductor device built on it,
It can be dried.

[Brief description of drawings]

1a is a sectional view of a wafer cassette holder of a semiconductor device manufacturing apparatus according to the present invention, FIG. 1b is a sectional view of a rotary dryer used in the present invention and a conventional example, and FIG. 2 is a wafer cassette of a conventional apparatus. It is sectional drawing of a holder. 1 ... Wafer cassette holder, 2 ... Wafer cassette, 3 ... Semiconductor wafer, 4 ... Contact, 5 ... Spring, 6 ... Support arm, 7 ... Grounding, 8 ... Rotating shaft, 9 ... Rotating mechanism, 10 ... Rotating drying device housing.

Claims (1)

[Claims] 1. A non-conductive and chemical-resistant wafer cassette on which a semiconductor wafer is loaded, and a wafer cassette which holds the wafer cassette and which itself revolves around a rotating shaft for rotating the semiconductor wafer and is electrically conductive. And while having a cassette holder having chemical resistance, while rotating the semiconductor wafer to scatter the liquid adhering to the semiconductor wafer by its centrifugal force to dry, the semiconductor wafer and the cassette holder mechanically. 1. A semiconductor device manufacturing apparatus comprising: a contact with a spring made of stainless steel 316 that contacts with a wafer cassette holder, and the wafer cassette holder is electrically grounded.