KR20030088409A - Batch type ashing apparatus using remote plasma - Google Patents

Abstract

PURPOSE: A batch type ashing apparatus using remote plasma is provided to be capable of preventing the damage of a substrate due to the plasma directly generated at the inner portion of a reaction chamber and reducing the time of an ashing process. CONSTITUTION: A batch type ashing apparatus is provided with a reaction chamber(10) for carrying out an ashing process, a plurality of batch type substrate support parts(50) spaced apart from each other in the reaction chamber for loading substrates, and a remote plasma generating part(30). The batch type ashing apparatus further includes a radical supply line(32) connected with the remote plasma generating part and vertically installed in the reaction chamber for supplying the radical generated from the remote plasma generating part to the substrates, and a gas exhaust pipe(40) for exhausting the gas existing in the reaction chamber.

Description

Batch type ashing apparatus using remote plasma

TECHNICAL FIELD The present invention relates to ashing apparatus, and more particularly, to a batch type ashing apparatus using a remote plasma.

Fabrication of semiconductor devices typically undergoes a photolithography process to form a pattern. In the photolithography process, a photoresist film is used as a mask layer, which must be removed after its function.

One method of removing the photoresist film is an ashing method, which is a method of oxidizing the photoresist film using plasma. Since the photoresist is made of a polymer of carbon (C) and hydrogen (H), oxygen plasma is usually used to vaporize it in the form of CO ₂ and H ₂ O.

Conventional ashing apparatus attaches a plasma electrode to a reactor and applies RF power with a frequency of approximately 13.56 MHz to it. That is, oxygen radicals are formed directly in the reactor to remove the photoresist film on the substrate. However, when the plasma is generated directly in the reactor, damage due to ion collisions in the substrate and the reactor occurs due to the relatively strong plasma. In addition, this method has a low radical production rate, the process efficiency is lowered, resulting in a process time increases resulting in a problem that the productivity is lowered.

The same process is repeated several times in the semiconductor device manufacturing process, and the photolithography process is the same. Therefore, the ashing process must also be repeated several times. In order to shorten the manufacturing time of the semiconductor device, it is necessary to shorten the time required for the ashing process.

As a method of increasing the ashing speed, there is a method of increasing the high frequency power applied for plasma generation, but in this case, high energy charged particles increase in the plasma in the reactor according to the increase of the power, which causes wear of the reactor internal parts and the surface of the substrate to be processed. Damage may be caused. In addition, as a method of increasing the ashing speed, there is a method of increasing the temperature of the substrate to be processed. However, when the substrate temperature is increased in an oxygen atmosphere, the surface of the substrate is oxidized and the electrical characteristics of the device are changed.

The technical problem to be achieved by the present invention, to prevent the substrate damage caused by the direct plasma generation in the reactor and to reduce the time required for the ashing process, using an ashing to load the substrate in a batch form using a remote plasma To provide a device.

1 and 2 are views for explaining a batch type ashing apparatus using a remote plasma in an embodiment of the present invention.

<Description of Reference Numbers for Main Parts of Drawings>

10: reactor 30: remote plasma generator

32, 32 ': radical supply furnace 32a, 32a': injection hole

40: gas exhaust pipe 50: substrate support

52: substrate

Ashing device according to the present invention for achieving the above technical problem, the ashing process is a reactor; A batch substrate support installed in the reactor such that horizontally placed substrates are stacked in a plurality of spaced apart from each other in a vertical direction; A remote plasma generator; A radical supply path installed vertically in the reactor and provided with a injection hole at a side thereof to supply radicals generated by the remote plasma generator between the substrates stacked on the substrate support; And a gas exhaust pipe for exhausting gas in the reactor; It characterized by having a.

The radical supply may be in the form of a tube, in which case at least two or more are preferably installed, and the inner diameter of the tube is preferably 5 to 25 mm.

The radical supply passage may be in the form of a plate.

A plasma electrode for applying RF power in the reactor may be further provided.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail. The following examples are only presented to understand the content of the present invention, and those skilled in the art may make many modifications within the technical spirit of the present invention. Accordingly, the scope of the present invention should not be construed as being limited to these embodiments.

1 is a view for explaining a batch type ashing apparatus using a remote plasma according to an embodiment of the present invention.

Referring to FIG. 1, a batch type substrate support 50 is installed in a reactor 10 in which an ashing process is performed, and the substrate support 50 is horizontally spaced apart from each other in a vertical direction by 2. A plurality of sheets of about 50 sheets are stacked.

As a process gas, for example, oxygen gas is supplied to the remote plasma generator 30 to form a plasma, and then oxygen radicals are supplied into the reactor 10 through the radical supply path 32. The radical supply path 32 is installed vertically in the reactor 10 so that radicals are supplied between the substrates 52, and a plurality of injection holes 32a are provided on the side thereof. The injection hole 32a is preferably located between the substrates 52.

A gas exhaust pipe 40 is installed in the reactor 10 to discharge gas generated by plasma ashing. For effective exhaust, the gas exhaust pipe 40 is preferably installed vertically, such as the radical supply path 32, and is disposed to face the radical supply path 32 with the substrate 52 interposed therebetween. A plurality of exhaust holes 40a are provided on the side facing 32.

In FIG. 2A, a tubular radical supply path 32 is shown, and in FIG. 2B, a plate-shaped radical supply path 32 ′ is shown. The injection holes 32a and 32a 'are provided in the side of each radical supply path 32 and 32'.

In the case where the radical supply passage 32 is tubular, at least the inner diameter must be at least 5 m to allow the radical to pass therethrough, but if the inner diameter is too large, the radical supply to the bottom of the reactor 10 may not be performed properly. It is preferable that it is 5-25 mm. Since it is difficult to uniformly supply radicals in an area corresponding to the width of the substrate as one tube, it is preferable that two or more radical supply paths 32 are provided as shown in FIG.

It is not necessary to apply a high frequency power of a high frequency to the remote plasma generator 30, and it is sufficient to form a plasma by applying RF power of 200 KHz to 2 MHz.

The reactor 10 may further include a plasma electrode 20 for applying RF power. The plasma electrode 20 may be applied with a RF frequency of a higher frequency than that applied to the remote plasma generator 30. Can be. If the high frequency power applied to the plasma electrode 20 is too high, this may cause wear of the internal parts of the reactor 10 and surface damage of the substrate 52, and therefore, RF power of 100 KHz to 13.56 MHz is preferably applied. Do.

Table 1 compares the photoresist etch rate in the case of directly generating plasma in the reactor (A) and using the remote plasma (B). An O ₂ plasma was used, and a photoresist was deposited on a SiO ₂ layer with a thickness of 15000 kPa. When the remote plasma is used, it can be seen that the excellent etching rate is shown.

Table 1

comparison target Pressure (torr) O2 (sccm) RF power (Kw) Etch Rate (Å / m) A 0.5 2000 1.5 400 B 0.5 2000 1.5 600

According to the present invention, since the substrate is charged in a batch type, the ashing efficiency is increased and the productivity is improved. In addition, the use of the remote plasma not only prevents wear of the reactor internal parts or damage to the substrate, but also increases ashing efficiency, thereby improving productivity. In addition, since the radical supply path is properly installed so that radicals are properly supplied between the substrates, all the substrates are uniformly ashed even when the number of substrates is large.

Claims (9)

A reactor in which the ashing process is performed; A batch substrate support installed in the reactor such that horizontally placed substrates are stacked in a plurality of spaced apart from each other in a vertical direction; A remote plasma generator; A radical supply path installed vertically in the reactor and provided with a injection hole at a side thereof to supply radicals generated by the remote plasma generator between the substrates stacked on the substrate support; And A gas exhaust pipe for exhausting gas in the reactor; Ashing apparatus comprising a. The ashing apparatus according to claim 1, wherein the radical supply passage is tubular. The ashing apparatus according to claim 2, wherein at least two radical supply passages are provided. The ashing apparatus according to claim 2, wherein the inner diameter of the tube is 5 to 25 mm. The ashing apparatus according to claim 1, wherein the radical supply passage has a plate shape. The ashing apparatus of claim 1, wherein the remote plasma generator is configured to form a plasma by applying RF power of 200 KHz to 2 MHz. The ashing apparatus according to claim 1, further comprising a plasma electrode for applying RF power in the reactor. The ashing apparatus of claim 7, wherein RF power of 100 KHz to 13.56 MHz is applied to the plasma electrode. The gas exhaust pipe of claim 1, wherein the gas exhaust pipe is vertically installed as the radical supply path and disposed to face the radical supply path with the substrate interposed therebetween, and a plurality of exhaust holes are provided on a side facing the radical supply path. Ashing apparatus, characterized in that provided.