KR20050047430A - Atomic layer etching apparatus and atomic layer deposition method there of - Google Patents

Abstract

An atomic layer thin film removing device includes a chamber for providing a predetermined thin film removing space; A lower electrode installed inside the chamber and seating the wafer on an upper surface of the chamber and providing a predetermined temperature condition to the wafer; And an upper electrode provided on an upper side of the wafer support, the upper electrode having a distribution function for removing an atomic layer overlying the upper surface of the wafer, and a gas supply tube for supplying a predetermined gas into the upper electrode. At least two kinds of reaction gases are alternately injected into the reaction chamber at regular time intervals by such a device, and purge gas is injected between the injections alternately to carry out a purge operation. In the atomic layer deposition method of sequentially stacking atomic layer thin films of a species, a process error occurrence rate is further included by detecting the thin film thickness of the atomic layer to be laminated and removing the atomic layer thin film when it exceeds the target thickness. Reduce

Description

Atomic layer thin film removal apparatus and atomic layer thin film deposition method using the same {ATOMIC LAYER ETCHING APPARATUS AND ATOMIC LAYER DEPOSITION METHOD THERE OF}

The present invention relates to a device for removing a thin film and a method for forming an atomic layer thin film using the same when the thin film is higher than a desired thickness in atomic layer deposition.

Recently, as semiconductor memory devices become more and more fine, attention has been paid to a technology for forming a uniform film by depositing a material for a thin film in a gaseous state on a substrate, for example, a method of growing a uniform thin film against irregularities of a fine pattern. Are largely classified into sputtering, chemical vapor deposition (CVD), atomic layer deposition (ALD), and the like.

In the sputtering method, argon (Ar) gas is injected into a vacuum chamber to which a high voltage is applied to form an inert gas, argon, in a plasma state, and then argon gas ions are blown to a target surface layer to target surface layer. And collide with each other and bounce the target particles due to the impact onto the substrate to deposit them.

This sputtering method is advantageous from the viewpoint of the purity and adhesion of the thin film, but the pattern in which the step is formed in the form of the unevenness, in particular, the thickness of the thin film deposited on the low level of the step is thin, making it difficult to secure uniformity. The application is very limited.

The thin film deposition by the chemical vapor deposition method is the most common technique to deposit a desired thickness on a substrate using a decomposition of the gas, that is, a gas, a desired thickness, a variety of gases are injected, and then heat to the gas A method of depositing a thin film of a predetermined thickness on a substrate by inducing chemical reactions of gases using energy such as light and plasma. The chemical vapor deposition method may control the heat, light, plasma, and the like to supply the reaction energy, or the deposition process may be performed at a high reaction rate by controlling the amount and ratio of the gas.

However, this reaction rate is generally very fast, which makes it difficult to control the thermodynamic stability of the atoms. In addition, such a method deteriorates the physical, chemical, and electrical properties of the thin film, and as pointed out in the description of the sputtering method, it is difficult to ensure uniformity of the thin film in minute unevenness.

On the other hand, the atomic layer deposition method is to alternately deposit a thin film of a single atomic layer by introducing a gas pulsing (gas pulsing) method, the recent high aspect ratio (Aspect Ratio) and the thin film of unevenness in accordance with the increase in the degree of integration of semiconductor devices It has been applied to meet the needs of forming thin films having uniformity and excellent electrical and physical properties. Here, the gas pulsing method means a method in which a reactive gas and a purging gas are alternately supplied. In addition, the thin film formation method using the atomic layer deposition method has the advantage that there is little residual impurities in the deposited thin film, and thickness control is easy even when depositing a thin film of less than 200 GPa.

The conventional atomic layer deposition apparatus includes a vacuum chamber and a heater for heating a substrate located in the vacuum chamber to an appropriate temperature applied at the time of thin film deposition, and a substrate holder (not shown) on an upper surface of the heater. One substrate is mounted on the substrate, and the substrate has a uniform temperature distribution by the heater. In the vacuum chamber, a shower head is provided so that a predetermined reaction gas is discharged to the substrate corresponding to the upper surface of the substrate.

In such an atomic layer deposition apparatus, a predetermined reaction gas is introduced into a vacuum chamber at a proper temperature through a shower head, and the reaction gas introduced into the vacuum chamber is deposited in a thin pattern of a fine pattern on a substrate. In addition, the remaining gas after vapor deposition is purged by the purging gas which alternately flows in and is discharged | emitted outside.

However, if the thickness of the thin film is higher than the desired value during the thin film deposition by the atomic layer deposition apparatus as described above, it is recognized as a process error and disposed of without further processing.

Accordingly, the present invention has been made to solve the above-described problems, the object of the present invention is to detect when the thickness of the thin film is greater than the reference value through the atomic layer deposition apparatus to remove the thin film to be reused It is to provide a thin film removal device.

Another object of the present invention is to detect the thickness of the thin film in the atomic layer deposition process and if the thin film is higher than the reference value to add a process to remove the thin film to form a thin film of the desired thickness and then continue to perform a series of processes To provide an atomic layer deposition method that allows.

According to a first aspect of the present invention, a chamber for providing a predetermined thin film removing space to achieve the above object; A lower electrode installed inside the chamber and seating the wafer on an upper surface of the chamber and providing a predetermined temperature condition to the wafer; An upper electrode provided on an upper side of the wafer support, the upper electrode having a distribution function for removing an atomic layer overlying the upper surface of the wafer; and a gas supply tube supplying a predetermined gas into the upper electrode; An atomic layer removal apparatus is provided.

The wafer support may be configured to form a plurality of divided zones to enable temperature control of the wafer into a plurality of regions.

The gas supply pipe is characterized in that a plurality is connected in order to supply different etching gas according to the type of the atomic layer.

A detecting unit for measuring the thickness of the atomic layer is further configured, the gas supply amount supplied to the shower head and the heating temperature conditions of the wafer support to reach the desired thickness value by comparing and analyzing the values measured from the detecting unit It characterized in that it further comprises a controller for outputting an operating condition for.

According to the second aspect of the present invention, at least two kinds of reaction gases are alternately injected into the reaction chamber at regular time intervals, and purge gas is injected between the alternate injections to perform a purge operation. In the atomic layer deposition method of sequentially stacking at least two kinds of atomic layer thin films on the surface, the process of removing the thin film through the atomic layer thin film removal apparatus if the thickness of the atomic layer thin film is more than the target thickness Provided is an atomic layer thin film deposition method further comprising.

Next, the structure and operation of the atomic layer thin film removing apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

As shown in FIG. 1, the atomic layer thin film removing apparatus 100 includes a chamber 110, a lower electrode 130, and an upper electrode 150.

The chamber 110 provides a predetermined atomic layer thin film removing space, and the lower electrode 130 is installed inside the chamber 110 and serves to seat and support the wafer W on an upper surface thereof. It is connected to the power supply 120 serves as an electrode. As shown in FIG. 2, the lower electrode 130 is composed of a plurality of divided zones so as to divide the wafer W into a plurality of regions to impart respective temperature conditions. The divided zone is divided into two center regions C1 and C2 and the circumference of the center region C2, for example, so that the top region T, the light region R, and the left region L are divided. ), And forms a bottom area (B).

Next, the upper electrode 150 is positioned at an upper end of the lower electrode 130 to be mainly grounded by a metal plate. Inversely, a high frequency power source may be connected to the upper electrode 150, and the lower electrode 130 may take a ground structure. The upper electrode 150 is provided with a buffer space 151 for receiving a predetermined gas supplied from a gas supply source (not shown). In this case, a plurality of through holes 153 is formed in the bottom of the buffer space 151 so that gas is injected to the upper surface side of the wafer W. On the other hand, a plurality of gas supply pipes (171, 173, 175) are connected to the upper side of the upper electrode 150, so that the respective gas supply source (181, 183, 185) to selectively supply the gas corresponding to the type of the atomic layer deposited on the upper surface of the wafer (W) Is supplied from.

On the other hand, one side of the chamber 110 is connected to the exhaust pipe 190 for exhausting the reaction by-product generated by the reaction of the supplied gas. In this case, the exhaust pipe 190 is further provided with a sensor 210 for detecting the flow amount of the reaction by-product, the controller 230 for comparing and determining the measured value detected through the sensor 210 is configured. Thus, the controller 230 outputs a signal for a process condition for the thin film thickness of the atomic layer to achieve a desired target based on the signal value transmitted from the detector 210. For example, the process condition satisfies the supply amount of gas supplied to the gas supply pipes 171, 173, and 175. At this time, the gas supply pipe (171, 173, 175) is preferably provided with a flow regulator (191, 193, 195) such as a valve or mass flow roller. In another example, the controller 230 is connected to the lower electrode 130 to adjust heating temperature conditions for each zone.

Next, the process of etching when the thickness of the atomic layer thin film exceeds the predetermined target value by the above-described configuration will be described.

A predetermined atomic layer () thin film is deposited on the surface of the wafer through a Munder, atomic layer thin film deposition apparatus (not shown). The atomic layer deposition is performed by injecting at least two reaction gases into the reaction chamber alternately at regular time intervals, and purge gas is injected between the injections alternately to carry out a purge operation. The atomic layer thin films are laminated sequentially. During the process, the thickness of the atomic layer is continuously detected, and if the thickness of the atomic layer exceeds a desired target value, the wafer W is removed from the atomic layer thin film removing apparatus 100 shown in FIG. Transferred to the upper surface of the lower electrode 130. Thereafter, after confirming the type of the atomic layer, a corresponding gas supply source is selected, and a predetermined gas is supplied through one of the gas supply pipes 171, 173, and 175, which is assumed to be supplied to 171. At the same time, the high frequency electrode is applied from the power supply 120 to the lower electrode 130 to cause the atomic layer to react by etching the gas supplied in the plasma atmosphere, thereby causing etching. At this time, the flow rate of the reaction by-product exhausted through the exhaust pipe 190 is checked by the sensor 210 and the measured value of the sensor 210 is transmitted to the controller 230 to compare with the reference value. Based on the comparison result, the controller transmits a signal to the flow controller 191 to adjust the supply amount of the gas supplied through the gas supply pipe 171 to adjust the degree of removal of the atomic layer thin film.

In this case, as another method of controlling the degree of removal of the atomic layer thin film, the lower electrode 130 may be divided by zone to control separate heating temperature conditions so that the atomic layer thin film may be removed for each part of the wafer (W). Will be.

As described above, the present invention provides an advantage in that, in the atomic layer deposition process, the thin film removal operation for removing the thin film when the thickness of the atomic layer exceeds the target value can be used to utilize a product which has been simply disposed of in the past. do.

As described above, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims below and equivalents thereof.

1 is a view showing the configuration of an atomic layer thin film removing apparatus according to an embodiment of the present invention,

2 is a plan view of the substrate support of FIG.

<Explanation of symbols for the main parts of the drawings>

100: atomic layer thin film removing device 110: chamber

130: lower electrode 150: upper electrode

171,173,175 Gas supply pipe 190 Exhaust pipe

210: detector 230: controller

Claims (5)

A chamber providing a predetermined thin film removal space; A lower electrode installed inside the chamber and seating the wafer on an upper surface of the chamber and providing a predetermined temperature condition to the wafer; An upper electrode provided on an upper side of the wafer support and having a distribution function of a gas for removing an atomic layer formed on an upper surface of the wafer; and And a gas supply pipe supplying a predetermined gas into the upper electrode. The method of claim 1, The wafer support is an atomic layer thin film removing apparatus, characterized in that to form a plurality of divided zones to enable temperature control of the wafer into a plurality of areas. The apparatus of claim 1, wherein a plurality of the gas supply pipes are connected to supply different gases depending on the type of the atomic layer. The exhaust pipe of claim 1, further comprising an exhaust pipe configured to exhaust reaction byproducts generated by performing a predetermined thin film removal process on one side of the chamber, and a detector configured to check a flow rate of the reaction byproducts. And a controller for comparatively analyzing the measured values from the measured values and outputting operating conditions for the gas supply amount supplied to the upper electrode and / or the heating temperature condition of the wafer support to reach a desired thickness value. Thin film removal device. At least two kinds of the atomic layer thin films on the substrate by injecting at least two kinds of reaction gases into the reaction chamber alternately at regular time intervals, and purging gas is injected between the two injections alternately. In the atomic layer deposition method of sequentially depositing, And removing the thin film through an atomic layer thin film removing apparatus when the thin film thickness of the stacked atomic layers is greater than a target thickness.