JPH0340418A - Washing device - Google Patents

Abstract

PURPOSE:To prevent diffusion contamination by a method wherein organic contamination is removed by jetting out cleaning gas to the rear side of a wafer at the same time when a baking operation is conducted. CONSTITUTION:A resist-coated wafer 2 is placed on the upper part of the protruding part 5 of a hot plate 1, and the wafer 2 is baked by the heat source 4 of the plate 1 under the above-mentioned condition. At the same time, when ozone-containing oxygen gas, fed from an oxygen supply source 8 and an ozone generator 9, is jetted out from a flow-out hole 7, ozone is heated up and decomposed by the baking heat, and a large quantity of oxygen atom radical is generated. An ashing treatment is conducted by allowing the above-mentioned radical to react with the organic contamination of the resist and the like adhered to the rear side of the wafer 2, and the contaminant is ashed and exhausted through the intermediary of an exhausting device 15. Accordingly, the organic contaminant on the rear side of the wafer 2 can be removed accurately in association with the heating when the baking operation is conducted, and the diffusion contamination can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a cleaning device used during baking in a resist processing process.

(Prior Art) The main steps in resist processing include resist coating and development. Among these, the spin coating method is often used in the resist coating process.

In this method, the wafer is suctioned and fixed on a spin chuck,
The wafer is rotated at high speed while the resist is dropped and spin-coated to uniformly coat the surface of the wafer. In this case, the resist is transmitted from the outer edge of the wafer to the backside of the wafer due to surface tension, and the resist adheres to the backside of the wafer.
After resist coating, a method is adopted in which the back surface of the wafer is cleaned by spraying a cleaning liquid from a nozzle provided in the coating device while rotating the wafer. Thereafter, a so-called pre-baking process is normally performed using a hot plate type oven through a conveyance path to volatilize the solvent in the resist.

(However, according to the above-mentioned conventional example, the back side of the wafer is cleaned by spraying a cleaning liquid while rotating the wafer after resist coating, but in this case, it is difficult to ensure that the back side is cleaned. Resist may be baked onto the hot plate during baking, or organic contaminants on the back side of the wafer due to chucking during the coating process or organic contaminants on the back side of the wafer in the transport path may be burned onto the hot plate during baking. There was also a risk that the wafer would be burned into the wafer, peel off, and adhere to the next wafer, or cause dust to be generated.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, it is an object of the present invention to prevent diffusion contamination by removing organic contamination by injecting a cleaning gas onto the back surface of a wafer simultaneously with baking.

Means for Solving the Problems In order to achieve the above object, the present invention arranges wafers at a distance on a baking hot plate, and connects flow channels provided on the hot plate. The cleaning gas was injected onto the back surface of the wafer through the wafer.

Further, it is preferable to use ashing gas as the cleaning gas.

(Function) Since the present invention is configured as described above, the wafer is transferred from the resist coating device to the next baking step via an appropriate transfer means, and the wafer is transferred onto the protrusion formed on the surface of the hot plate in the baker. When baking is performed with the wafer placed on the hot plate, at the same time, a cleaning gas, such as ashing gas, is supplied to the channel provided in the hot plate and the cleaning gas is injected from the jet nozzle on the hot plate surface. Accordingly, organic contamination on the back surface of the wafer can be reliably removed and diffusion contamination can be prevented.

(Example) An example in which the present invention is applied to a cleaning device for baking will be described below with reference to the drawings.

A hot plate 1 provided in the baker is used to bake the spin-coated film 2 in the resist coating process and volatilize the solvent in the resist.
In this example, a heat source 4 connected to a temperature control device 3 is built into the hot plate 1 to heat the plate to about 80 to 160°C.

Further, an appropriate number of protrusions 5 for placing the wafer 2 are provided on the upper surface of the hot plate 1, and the wafer 2 is placed on the upper part of the protrusions 5, so that the back surface of the wafer 2 and the top of the hot plate are connected. For example, the wafer 2
The structure is such that proximity baking is performed so that the back surface of the device is not brought into full contact with the other surface.

Furthermore, a channel 6 for supplying cleaning gas is formed in the hot plate 1, and an appropriate number of jet ports 7 are formed in the channel 6 on the top surface of the hot plate 1 to supply the cleaning gas to the back surface of the wafer 2. I'm trying to spray it. Moreover, in this example, the cleaning gas is supplied from the supply port 6a of the flow path 6. , Arasin gas containing ozone is used. The arasin gas of this example is produced by controlling oxygen gas containing ozone supplied from an oxygen supply source 8 and an ozone generator 9 to a flow rate of 0, for example, using a gas A amount regulator 10.
．． The concentration is adjusted to about 1 to 1 Q /min, and the concentration is about 100 to 200 g /m, and is supplied from the top of the supply pipe 1.

On the other hand, an exhaust port 12 is formed on the top surface of the hot plate 1,
The exhaust port 12 is configured to exhaust the cleaned waste and waste through an exhaust flow path 13 by an exhaust device 14 through an exhaust pipe 14.

Next, the operation of the above embodiment will be explained.

Wafer 2 coated with resist in a resist coating device
The wafer 2 is transferred to the next baking step via an appropriate transfer means, and the wafer 2 is placed on top of the protrusion 5 formed on the surface of the hot plate 1 in the baker. So-called pre-baking is performed in which the wafer 2 is baked to volatilize the solvent in the resist. At the same time, when the oxygen gas containing ozone supplied from the oxygen supply source 8 and the ozone generator 9 is adjusted by the gas flow rate regulator 10 and injected from the jet port 7, the ozone is heated by the heat of baking and decomposed. However, a large amount of oxygen atom radicals are generated. Then, these radicals react with organic contaminants such as resist attached to the back surface of the wafer 2, and ashing is performed, and the contaminants are removed.
Since it is ashed and exhausted through the exhaust device 15, organic contamination on the back surface of the wafer 2 caused by heating during baking can be reliably removed and diffusion contamination can be prevented.

Although the above example describes baking after the resist coating device, the present invention is not limited to this, but is also applicable to a hot plate for post baking performed after development. The cleaning gas may be any gas other than the ashing gas, depending on the implementation.

Effects of the Invention As is clear from the above, the present invention has the following useful effects.

Diffusion contamination can be prevented by injecting cleaning gas onto the backside of the wafer at the same time as baking to reliably remove organic contamination attached to the backside of the wafer.
As a result, there are effects such as being able to contribute to an improvement in yield.

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[Brief explanation of drawings]

1...Hot plate 4...Heat source 5...Flow path 2n■ wafer 5... Protrusion 7... spout

Claims (2)

[Claims] (1) A cleaning device characterized in that the wafers are arranged at a distance on a baking hot plate, and a cleaning gas is injected onto the back surface of the wafers through a flow path provided in the hot plate. (2) The cleaning device according to claim 1, wherein ashing gas is used as the cleaning gas.