JPS63260034A - Asher - Google Patents

Abstract

PURPOSE:To improve the uniformity and the treatment speed of ashing by forming inclined parts at a side end part of a plane facing to a treated substrate with respect to ashing gas orifices and exhaust gas suction ports. CONSTITUTION:An ashing gas is produced through an ozonizer 21 connecting to an oxygen supply source 20 by controlling a heater 15 which is built in a stage 13 with a temperature control device 14, thereby heating a semiconductor wafer 12 and the ashing of the semiconductor wafer 12 is treated by adjusting the flow rate of the above ashing gas with the gas flow regulator 19 and by causing its gas to flow out from gas orifices 17a-17e of a gas outflow exhaust port 17 to the semiconductor wafer 12 surface. After ashing treatment, the ashing gas is exhausted from exhaust gas suction ports 17f-17j of the gas outflow exhaust port 17. At a plane facing to a treated substrate between respective slit holes, slanted parts 17k-17u having angles, for example, 1-30 deg. are prepared by having alternate angles so that the ashing conditions may become adequate to the treated substrate. This inclination serves to promote the uniform diffusion of the outflow of the ashing gas and also to suck and collect larger amounts of the exhaust gas.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (Field of Industrial Application) The present invention relates to an ashing device for removing unnecessary films deposited on a substrate to be processed.

(Prior art) Generally, fine patterns for semiconductor integrated circuits are formed by etching a base film formed on a semiconductor wafer using an organic polymer photoresist film formed by exposure and development as a mask. . Therefore, the photoresist film used as a mask must be removed from the surface of the semiconductor wafer after the etching process.

Ashing processing is performed to remove the photoresist film in such cases. In particular, ashing processing using plasma is the mainstream. However, as the degree of integration of semiconductors improved, the number of bits increased from 256 bits to 1M bits.
In the case of a 4M bit ultra-super LSI, the formation area for each element, such as active elements and wiring, becomes narrower and the intervals between them become narrower, and when processed in a plasma atmosphere, electrical discharges occur between elements such as wiring, damaging the semiconductor wafer. This results in a decrease in yield.

Furthermore, there is an ashing device that generates oxygen atom radicals by irradiating ultraviolet rays and performs ashing processing in batch processing.

No. 7rjA shows an ashing device using such ultraviolet rays, in which a large number of semiconductor wafers 2 are arranged vertically at predetermined intervals in a processing chamber 1, and an ultraviolet light emitting device installed at the upper part of the processing chamber 1 is used. Ultraviolet rays from the tube 3 are irradiated through a transparent window 4 made of quartz or the like provided on the upper surface of the processing chamber 1, and oxygen filled in the processing chamber 1 is excited to generate ozone. Then, oxygen atom radicals generated from this ozone atmosphere act on the semiconductor wafer 2 to perform an ashing process.

(Problems to be Solved by the Invention) However, in the conventional ashing device using ultraviolet rays described above, the ashing speed is 50 to 150 nm/wi.
There is a problem that single wafer processing, which is suitable for processing large-diameter semiconductor wafers, cannot be performed, for example, because the processing time is slow.

As a means to solve these above-mentioned problems, JP-A-52-2
There is an ashing device that thermally excites ozone gas, as disclosed in Japanese Patent No. 0766. However, although we have commercialized and developed these devices, the larger the wafer diameter, the more noticeable ashing occurs.
Uniform ashing development was being carried out.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide an ashing device that improves the uniformity of ashing and the processing speed, and that can handle single-wafer processing of large-diameter semiconductor wafers and does not cause damage. It is something to do.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides an apparatus for performing ashing processing in which a plate having an ashing gas outlet hole and an exhaust gas suction hole is provided opposite to a substrate to be processed. A slanted portion is formed at the end portion of the surface facing the substrate to be processed.

(Function) Suction holes are provided to prevent the accumulation of exhaust gas after the ashing process on a plate having outflow holes for ashing gas arranged opposite to the substrate to be processed, and an inclined surface is provided to improve the flow between these suction holes and outflow holes. This improves the ashing rate and uniformity by promoting the flow of ashing gas.

(Example) Hereinafter, an example in which the apparatus of the present invention is applied to an ashing process in a semiconductor manufacturing process will be described with reference to the drawings.

In FIG. 1, a mounting table 13 is provided in a processing chamber 11 to hold a substrate to be processed, such as a semiconductor wafer 12, by suction using, for example, a vacuum chuck. This mounting table 13 has a heater 1 whose temperature is freely controlled by a temperature control device 14.
5 is installed inside, and is set to be vertically movable by a lifting device 16.

A gas outflow suction section 17 made of a sintered body of metal or ceramic, for example, is provided above the mounting table 13. The area around this gas outflow/suction section 17 is cooled by cooling water or the like circulated from a cooling device 18 in order to prevent ozone from being decomposed in the flow path.

Further, the gas outflow/exhaust section 17 is provided with a plurality of slit holes 17a to 17j on the side facing the substrate to be processed, and the ashing gas outflow holes 17a=17e are used to adjust the gas flow rate so as to irradiate the surface of the semiconductor wafer 12 with the ashing gas. The ozone generator, which is connected to the oxygen supply source 20 through the vessel 19, is connected to the earthenware 21 with a Teflon gas pipe of, for example, low-tension 81w, while the exhaust gas suction holes 17f-17j are connected to the exhaust device 22, with a diameter of 8m+a, for example. It is connected with a Teflon gas pipe. The ashing gas after the ashing process is decomposed by an exhaust gas treatment, for example, an ozone decomposer (not shown), and is discharged by the discharge device 22.

The slit holes of the gas outflow/discharge section 17 are alternately provided with, for example, gas outflow holes 17a to 17e and exhaust gas suction holes 17f to 17j in order to eliminate the accumulation of ashing gas, and the surface facing the substrate to be processed between each slit hole is provided with Slanted portions 17k"17u designed to allow for gas flow to provide appropriate ashing conditions at an angle of, for example, 1 to 30" with respect to the substrate to be processed.
are placed at alternating angles. This slope promotes uniform diffusion of the ashing gas flowing out, and has the effect of suctioning and collecting more exhaust gas.

Next, the ashing operation of the semiconductor wafer by the above-mentioned ashing apparatus will be explained.

The mounting table 13 is lowered by the lifting device 16, and a gap is provided between the mounting table 13 and the gas outflow/discharging section 17 for introducing, for example, a hand arm or the like of a wafer transport device (not shown), and the semiconductor wafer 12 is placed on the mounting table 13 by the wafer transport device or the like. It is placed on the mounting table 13 and held by suction. At this time, the semiconductor wafer 12
Elements with the same characteristics can be manufactured with good reproducibility by performing orientation flat alignment as necessary.First, the mounting table 13 is raised by the lifting device 16 and the processing chamber is set in a sealed state.

The gas outflow/discharge portion 17 is provided at a distance of, for example, about 0°5 to 20 m from the surface of the semiconductor wafer 12. In this case, the gas outflow discharge part 17
may be moved up and down by a lifting device.

Thereafter, the heater 151 built into the mounting table 13 is controlled by the temperature control device 14 to heat the semiconductor wafer 12 to a temperature in the range of, for example, 150 to 500°C, and the oxygen supply source 2
The ashing gas generated by the ozone generator 21 connected to
Adjust the flow rate to about 15SQ/aIin (flow rate converted to normal temperature and pressure), and
It flows out from a to 17e onto the surface of the semiconductor wafer 12 and performs an ashing process on the semiconductor wafer 12.

The ashing gas after the ashing process is discharged from the gas outflow discharge section 1.
The exhaust gas is discharged from the exhaust gas suction holes 17f to 17j of No.7.

The gas outflow discharge part 17 only needs to be larger than the substrate to be processed;
For example, the width between the lines is 0.5 to 5 II as shown in Figure 2.
A slit hole 17a with a depth of about 5 to 15 mm at about Il.
17j, and gas outlet holes 17a to 17e and exhaust gas suction holes 17f to 17j are provided alternately at, for example, a hole interval of about 5 to 30 m, and the surface facing the substrate to be processed between each slit hole is as shown in FIG. The flow of the ashing gas is constricted in the vicinity of the exhaust gas suction holes 17f to 17j to form a slope suitable for the ashing process conditions.If there is no slope, the flow of the reaction gas is as shown in FIG. As a result, the ashing rate decreases at the exhaust gas suction hole. On the other hand, when there is the inclined part.

As shown in FIG. 5, uneven ashing at the exhaust gas suction hole can be prevented, and ashing uniformity and processing speed can be improved.

The ashing gas after the ashing process by the method described above is decomposed by an ozone decomposer (not shown), and then sent to the discharge device 2.
Exhaust from 2.

This completes the ashing process for the semiconductor wafer 12, and the semiconductor wafer 12 is transported to the next process by a transport mechanism (not shown).

In this embodiment, the gas outflow discharge part 17 has a disk shape as shown in FIG. 2, and the linear gas outflow hole 17a=1.
7e and the exhaust gas suction holes 17f to 17j are arranged alternately, but the present invention is not limited to this embodiment, and the gas outflow/discharge portion may have a rectangular shape, for example, a concentric shape as shown in FIG. The gas outflow/discharge section may be provided with slit holes 23a to 23j, and the arrangement and number of the outflow and suction slit holes need only be suitable for the ashing process.

In addition, although the inclined portion 17 of the surface facing the substrate to be processed between the slit holes in this example was formed with an inclination angle of about 1 to 30 degrees, the gas flow was such that the ashing conditions were appropriate. Needless to say, it is only necessary that it be parallel to the substrate to be processed.

As described above, according to this embodiment, a gas flow suitable for ashing processing is realized by providing an inclined portion on the surface facing the substrate to be processed between the linearly formed outflow/suction slit holes. Preventing uneven ashing improves processing speed and uniformity.

〔Effect of the invention〕

As described above, according to the present invention, the uniformity of ashing and processing speed of the substrate to be processed can be improved, and single-wafer processing of large-diameter substrates to be processed can be performed without damage.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an ashing device for explaining one embodiment of the present invention device, Fig. 2 is a block diagram of the gas outflow discharge section shown in Fig. 1, and Fig. 3 is a block diagram of the gas outflow discharge section shown in Fig. 2. Figures 4 and 5 are diagrams showing the influence of the flow of ashing gas on processing when the ashing device of Figure 1 is provided with and without the inclined section, and Figure 6 is FIG. 7 is a diagram showing a modification of the gas outflow/discharge section shown in FIG. 2, and FIG. 7 is a configuration diagram showing a conventional ashing device. 11... Processing chamber 12... Semiconductor wafer 13... Mounting table 15... Heater 17
...Gas outflow discharge part 17a=17j, 23a-23j...Slit hole 17
~17u... Inclined portion Patent applicant Tokyo Electron Ltd. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] In an apparatus for performing ashing processing in which a plate having an ashing gas outlet hole and an exhaust gas suction hole is provided facing the substrate to be processed, an inclined portion is formed at the end of the ashing gas outlet hole and the exhaust gas suction hole on the side facing the substrate to be processed. This ashing device is characterized by: