JPH03205823A - Ashing device - Google Patents

Abstract

PURPOSE:To obtain an ashing device which can handle 50 sheets and is compact and free of pollution occurrence by performing the ashing treatment from the upper stage of a wafer cassette to the lower stage. CONSTITUTION:In a method of providing two wafer cassettes 1, putting wafers in both cassettes 1, taking out wafers from the wafer cassettes 1, ashing the wafers and returning the wafers 1 after the treatment to the same stage of the wafer cassettes 1, the treatment is done from the upper stages of the wafer cassettes 1 to the lower stages. For example, wafers are set in the wafer cassettes 1 and 1, and a wafer of each cassette 1 is taken out by a carrier 2, and they are loaded in treatment rooms 3 to do ashing treatment. The wafers after ashing treatment are stored in the same stages of the wafer cassettes 1, and next wafers at lower stage are taken out and the treatment is repeated. And a cleaning arm 4 is inserted in the vacant stage of the wafer cassette in the course of treatment to do cleaning by supplying ultraviolet rays and ozone.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an ashing device, and particularly an ashing device provided with means for preventing contamination of wafers in a method of returning processed wafers to the same stage of a wafer cassette. Regarding.

[Conventional technology]

For example, "Optical ashing technology" SEMICON News (SEM
ICON NEILS), 1988, No. 12 discloses an apparatus that processes wafer cassettes by dividing them into a loader side and an unloader side. In such processing, the wafer is not contaminated during processing. However, with this conventional method, only 25 wafers can be set, and generally 50 wafers can be set.
This is inconvenient when working in batches.

For this purpose, both wafer force sets are packed with wafers (
50 wafers), the wafers are pulled out, and after processing, the wafers are returned to the same stage from which they were pulled out.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, when processing wafers from the lower stage of the wafer cassette, when unprocessed wafers from the upper stage are taken out from the clean wafers after processing, dust such as resist falls off and contaminates the clean wafers below. It turns out.

Furthermore, if unprocessed wafers are pulled out and resist or the like is attached to the stage, this deposit will contaminate the wafers since the clean wafers after processing are returned to the same stage.

The present invention improves these drawbacks and allows processing of 50 sheets.
An object of the present invention is to provide an ashing device that is compact and does not cause contamination.

[Means to solve the problem]

In order to achieve the above object, the present invention has the following means.

1. Start processing wafers from the top of the wafer cassette, with unprocessed wafers always below clean wafers after processing.

2. Ultraviolet rays are irradiated and ozone is supplied to empty wafer cassette stages during wafer processing.

[Effect]

1. By always performing processing from the top of the wafer cassette, unprocessed wafers are positioned below processed wafers, and even if resist, etc. falls when unprocessed wafers are pulled out, they will not be placed on top of unprocessed wafers. The wafers are kept clean after processing.

2. Dirt on the empty wafer cassette that adheres when the wafer is pulled out is cleaned using so-called UV/Ca cleaning by UV irradiation and ozone supply, so that even if the wafer is returned after processing, it will not be contaminated. It disappears.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In FIG. 1, wafers (not shown) are set in wafer cassettes 1, 1', taken out by a carrier 2,
It is stored in the processing chamber 3 and subjected to ashing processing. The wafers after ashing are stored in the same stage of the wafer cassette l, and then the wafers in the lower stage are taken out and the above-mentioned process is repeated. Thus, in the present invention, processing begins at the top of the wafer force set and moves to the bottom.

Next, the cleaning arm 4 is inserted into the empty stage of the wafer cassette being processed, and ultraviolet rays and ozone are supplied to clean the empty stage during the wafer processing time. Immediately before the processing of the wafer is completed, the cleaning arm is retracted, and the processed wafer is returned to the cleaned empty stage.

At this time, due to space limitations, we placed 1' on the wafer cassette.
There is also a method of rotating the cleaning arm by, for example, 45 degrees to make it easier to install the cleaning arm (see Figure 2).

As shown in FIG. 3, the structure of the cleaning arm is such that ultraviolet light is introduced through an optical fiber 5 and ozone is supplied through a separate tube 7.

In addition, to prevent ozone leakage, a cover (not shown) is provided over the entire atssia, which is pulled through a duct, and ozone is extinguished by an ozone decomposer.

Here, in FIG. 3, reference numeral 6 indicates a quartz blank for irradiating ultraviolet rays into the cassette holder, and reference numeral 8 indicates a slit for blowing out ozone.

In addition, in FIG. 1, the horizontal movement mechanism of the cleaning arm is not shown.

〔Effect of the invention〕

According to the present invention, 50 wafers can be processed with two cassettes, the apparatus can be made smaller, and the operating efficiency can be increased.

Furthermore, since processing starts from the top of the wafer cassette and moves to the bottom, objects falling from the wafers will not fall onto the processed wafers.

Furthermore, since the empty stage is cleaned by the cleaning arm, the wafers after processing can be kept even more clean.

[Brief explanation of drawings]

FIG. 1 is a side view of an ashing device according to an embodiment of the present invention;
2 is a plan view of the device shown in FIG. 1, and FIG. 3 is a partial sectional view of a cleaning arm provided in the ashing device according to an embodiment of the present invention.

Claims (1)

[Claims] 1. Two wafer cassettes are installed, wafers are placed in both of them, the wafer is taken out from the wafer cassette, the ashing process is performed, and the processed wafer is placed in the same wafer cassette (from which the wafer was taken out). This ashing device is characterized by processing wafer cassettes from the upper stage to the lower stage in a single stage returning method. 2. The ashing apparatus according to claim 1, further comprising means for cleaning the empty stage of the wafer cassette by irradiating ultraviolet rays and supplying ozone to the empty stage of the wafer cassette (during unloading of the wafer) during wafer processing.