KR100220246B1 - Plasma etching apparatus and etching method - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma etching apparatus and an etching method for selectively removing a film formed on a surface of a wafer in a semiconductor manufacturing process, wherein the structure and etching method of the plasma etching apparatus are improved to be used continuously in the process. By using the plasma only for the initial state and the etching process, it is possible to prevent the shortening of parts life and the generation of particles due to the damage of the process kit, and to prevent the cooling failure of helium gas caused by incorrect fixing of the wafer due to the damage of the E chuck. In addition, an object of the present invention is to stably maintain the sealed state in the chamber, and the present invention provides a top side portion of the process chamber and includes a side portion made of quartz, a liner continuously positioned at the bottom of the side portion, and a bottom portion on which the wafer is placed. It consists of wafer pedestal and E chuck as A heated antenna assembly is provided at a rear side of the quartz side surface, a source power source for generating plasma is connected to one side of the antenna assembly, a stage power source is connected to a lower end of the wafer pedestal, and a chamber is connected to a lower end of the chamber. In the plasma etching apparatus provided with the injection hole for providing the reaction gas in the inside, The said process chamber is characterized by two.

Description

Plasma Etching Equipment and Etching Method

The accompanying drawings are cross sectional views illustrating a process chamber in a plasma etching apparatus.

* Explanation of symbols for main parts of the drawings

1: upper surface 2: side

3: liner 4: wafer

5: wafer stand 6: E chuck

7: antenna assembly 8: source power

9: stage power supply 10: reaction gas inlet

[Field of Invention]

The present invention relates to a plasma etching apparatus and an etching method for selectively removing a film formed on a surface of a wafer in a semiconductor manufacturing process.

[Prior art]

In general, there are processes for forming a thin film on the front surface of a wafer, such as silicon dioxide, silicon nitride, or a metal, in an integrated circuit manufacturing process. At this time, the process of selectively removing the thin film of the unwanted site is called an etching process. There are various forms according to product requirements, such as removing thin films in a round circular shape and leaving thin films on the wafer surface in a long line.

The etching process includes wet chemical etching, electrochemical etching, pure plasma etching, reactive ion etching, ion beam milling, sputtering and hot steam etching according to the method.

On the other hand, since the etching process does not occur only a portion of the surface of the wafer, the use of an etching resist material (Etching Resist Material) is required to leave a thin film of the required portion. Most integrated circuit etching processes are performed in the following order to achieve selective etching.

1. Wafer surface coating of Etch-Resistant Photoresist.

2. Optional process to memorize the desired pattern.

3. An etching process for transferring the pattern to the lower layer thin film.

4. The step of cleaning the surface after removing the photoresist.

In addition, the etching process is divided into isotropic etching and anisotropic etching according to the etching characteristics, isotropic etching is mainly shown in the wet etching, it can also be obtained according to the change of parameters (parameter) during the etching using plasma.

In contrast, anisotropic etching can be obtained by plasma etching, but hardly by wet etching.

As another classification, the etching process may be classified into wet etching and dry etching, where wet etching means all kinds of etching mainly using liquid chemicals, and plasma etching comprehensively covers all etching processes using plasma. It also means.

The wet etching mainly uses chemicals as described above, and is used for the purpose of isotropic etching, and dry etching is mainly used for the purpose of anisotropic etching. However, wet etching is still partly used in high integrated circuit manufacturing processes due to the many advantages of chemical reactions. Dry etching has been referred to as plasma etching because it usually uses a reaction in a "plasma" state, and as the degree of integration requires the formation of finer shapes, the technique of dry etching is also required as an ideal anisotropic etching is required. It has evolved in many ways.

Early dry etching was referred to as plasma etching because it was simply using plasma, but since then, various developments have been made depending on how the plasma is controlled or how the substrate is positioned.

Initially, dry etching was called plasma etching because it was simply a method of floating the material to be etched in the plasma. However, dry etching has been developed through the control of the position of etching material or plasma potential. It was.

As one of the dry etching apparatus using the plasma, an apparatus called a Centura 5300 HDP is used, and a process chamber of the apparatus is illustrated in the accompanying drawings.

As shown, the process chamber comprises a top surface 1 composed of a silicon plate, a top side portion 2 of quartz and a liner continuously positioned at the bottom of the side portion 2. 3) and a wafer pedestal 5 and an E chuck 6 as the lower end on which the wafer 4 is to be placed, wherein the rear side of the quartz side portion 2 is provided with a heated antenna assembly 7. A source power source 8 for generating a plasma is connected to one side of the antenna assembly 7, and a stage power source 9 is connected to a lower end of the wafer pedestal 5 so that the chamber is connected to the chamber by the two power sources 8 and 9. High density plasma is generated within. In addition, the lower end of the chamber is provided with an injection port 10 for providing a reaction gas in the chamber.

In addition, the E chuck 6 does not fix the wafer by physical contact but maintains the wafer in a fixed position by static electricity formed around the E chuck 6. In addition, helium gas is generated at the rear surface of the wafer fixed by the E chuck 6 to prevent excessive temperature rise of the wafer by plasma etching.

In the apparatus, all three such chambers are provided, and each chamber has a drastic difference in temperature used for each part of the chamber, and only one robot provides a wafer and moves the etched wafers within the three chambers. As one of the three independent chambers is continuously rested, the etching rate of each chamber is severely changed according to the idle time during the process, and thus, the quartz chamber, the liner, Continuous plasma is used to heat process kits, such as wafer flaps.

According to a series of processes using the continuous plasma, first, preheating the chamber by the continuous plasma, adjusting the conditions until the state in the chamber is stabilized as a preliminary process, and the main etching process step; In this case, continuous plasma is applied at all stages, and the temperature control in the chamber can be made constant by the use of the continuous plasma.

[Technical problem to be achieved by the present invention]

By the way, in the above-described conventional plasma etching apparatus, in order to keep the etching rate per chamber constant by maintaining the temperature in the chamber resting by the use of the continuous plasma, the plasma in the chamber can be kept constant. Since the process kit is damaged by the plasma to shorten the parts life of each part, and particles from the process kit are generated, the E chuck is damaged by the continuous plasma. Therefore, there is a problem in that the wafer cannot be maintained in a normal position and the cooling of the wafer by the helium gas fails, as well as the sealing state in the chamber is also damaged, so that the vacuum state cannot be maintained accurately.

Therefore, the present invention has been made to solve the above-described problems, and by improving the structure and etching method of the plasma etching apparatus, by using the plasma continuously used in the process only in the initial state and the etching process, It aims to prevent shortening of parts life and particle generation by damage to the kit, and to prevent the cooling failure of helium gas caused by incorrect fixing of the wafer due to E chuck damage, and to keep the sealing state in the chamber stable. do.

[Configuration and Function of Invention]

In order to achieve this object, the present invention comprises a side portion of the process chamber and made of quartz, a liner continuously positioned at the bottom of the side portion, a wafer pedestal and an E chuck as the bottom portion on which the wafer is placed. The rear side of the quartz side portion is provided with a heated antenna assembly, one side of the antenna assembly is connected to a source power source for generating a plasma, a stage power source is connected to the bottom of the wafer pedestal, and In the lower end portion, the plasma etching apparatus is provided with an injection hole for providing the reaction gas in the chamber, characterized in that the two process chambers.

The process chamber has a drastically different temperature for each part of the process chamber, and a plasma etching method using continuous plasma to heat process kits such as a quartz chamber, a liner, and a wafer clamp. In the first operation of the etching apparatus, the preheating time of the first chamber is set to 524 seconds, and the preheating time of the second chamber is set to 564 seconds. It is characterized in that the two chambers are operated continuously with a certain time difference by the wafer movement time by the robot.

In addition, if the process between the first chamber and the second chamber is continuously executed through the initial preheating process, since the idle time between the chambers is about 40 seconds, the subsequent process is performed without the preheating process by plasma. It is desirable to be able to carry out the etching process.

EXAMPLE

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. In this embodiment, the same reference numerals are assigned to the same parts as those cited in the related art, and will be described again to avoid duplication of description. I never do that.

First, in the Centura 5300 HDP apparatus, when the idle time in the process chamber is 60 seconds or less during the process performed by the plasma etching apparatus, the etch rate change between the chambers is not affected. .

Therefore, according to the present invention, the process chambers in the etching apparatus is reduced from three to two, so that when the process in one chamber proceeds, the remaining chambers remain in the standby state, so that there is no resting chamber, and also the chambers By adjusting the preheating time, the plasma is not generated continuously.

That is, when the device is first operated, the preheating time of the first chamber is set to 524 seconds, and the preheating time of the second chamber is set to 564 seconds, and the robot is allowed to leave the robot during the time. The wafer travel time by means of the two chambers are operated continuously with a certain time difference.

Therefore, when the process between the first chamber and the second chamber is continuously executed in the early stage of the preheating process, the idle time between the chambers is about 40 seconds, which is why the subsequent process does not require the preheating process. It is possible to carry out a continuous etching process.

Thus, according to the present invention, plasma is not continuously generated throughout the entire process in order to preheat the process kit in the chamber.

[Effects of the Invention]

As described above, according to the plasma etching apparatus and the etching method according to the present invention, by reducing the process chambers of the etching apparatus to two, the efficiency of the chamber is increased, and the continuous plasma is not used. In addition, the improvement of component life in the chamber and the generation of particles are suppressed, and furthermore, the E chuck damage is prevented, thereby preventing the cooling failure of the wafer.

The present invention has been illustrated and described above with respect to certain preferred embodiments, but the present invention is not limited to the above-described embodiments, and the present invention belongs without departing from the spirit of the invention as claimed in the claims. Anyone with ordinary knowledge in the field will be able to make various changes.

Claims (2)

A plasma etching method in which a continuous plasma is used to heat a process kit, such as a liner and a wafer clamp, provided in a process chamber made of quartz whose temperature used for each of the internal parts is significantly different. At the time of initial operation, the preheating time of the first chamber is set to 524 seconds, the preheating time of the second chamber is set to 564 seconds, and the preheating time between the chambers is allowed for about 40 seconds. Plasma etching method characterized in that the two chambers are operated continuously with a constant parallax. The method of claim 1, wherein if the process between the first chamber and the second chamber is continuously performed through the initial preheating process, the idle time between the chambers is about 40 seconds. A plasma etching method, characterized in that it is possible to carry out a continuous etching process without going through.