JPS6147645A - Formation of thin film - Google Patents

Abstract

PURPOSE:To remarkably improve deposition rate of film and thereby improve productivity by heating the surface of target material to be sputtered. CONSTITUTION:The flat electrodes 2, 3 are provided opposed to each other within a sputtering chamber vessel 1, an upper electrode 2 is generally grounded and a substrate 4 is placed on this electrode 2 with a substrate support 5. In the case of forming a silicon oxide film, for example, a target material 8 consisting of quartz glass is placed on the electrode 3. A heater 9 for heating target is buried within the electrode 3. After the inside of vessel 1 is exhausted to the vacuum condition of about 1X10<-6>(Torr), the Ar gas, for example, is supplied from the gas supply port 11 and the gas pressure in the vessel 1 is kept at 10[mTorr]. Next, the heater 9 is heated by a power supply 10 until the surface of target 8 is heated up to about 450 deg.C and thereafter a high frequency power 7 is set for example to 7[kW] to generate discharge between the electrodes 2, 3. The target material 8 is sputtered with the Ar ion and silicon oxide film is deposited on the surface of substrate 4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in a thin film forming method using a sputtering method.

[Technical background of the invention and its problems]

Conventionally, a sputtering method has been used as one method for forming a thin film on a substrate such as a semiconductor wafer. In general sputtering method, 161 to 10 [Torr]
Ions generated by discharge in a vacuum of about 100 mL are accelerated and bombarded with a target electrode. At this time, constituent atoms of the target material are ejected by ion sputtering.

A thin film is then formed by depositing atoms released from this target material onto a substrate.

However, this type of method has a problem in that the film deposition rate is slow and it takes a long time to obtain a desired film thickness. That is, although the deposition rate of a film can be faster than the sputtering conditions lζ such as power supply output and pressure, the deposition rate of an insulating film such as a silicon oxide film is usually 100 [
A/1 m1n] Even if magnetron sputtering is used, it is several times slower than this. Therefore, in order to increase productivity, it is necessary to increase the target area and form films on multiple substrates simultaneously, but in this case, the power supply capacity needs to be increased and the equipment is also expensive. becomes.

[Purpose of the invention]

An object of the present invention is to provide a thin film forming method that can significantly increase the film deposition rate and improve productivity without requiring any fundamental improvements to sputtering equipment. .

[Summary of the invention]

The gist of the present invention is to increase the surface temperature of the target material and increase the amount of atoms emitted from the target material by sputtering.

Conventionally, the target material is generally water-cooled during sputtering. The amount of atoms emitted from the target material increases as the surface temperature of the target material increases.

The present invention focuses on this point, and employs a sputtering method in which a target material is sputtered with ions generated by discharge to form a thin film on a predetermined substrate surface (in this case, the surface temperature of the target material is This method is designed to increase the

〔Effect of the invention〕

According to the present invention, when the accelerated ions approach the target, the temperature of the target surface is higher than before, so
The amount of atoms sputtered from the target increases. This is because sputtering efficiency is temperature dependent, and the higher the temperature, the higher the sputtering efficiency. For example, human r ion is 8i0. When sputtering a target, if the temperature of the target surface is raised to 450° C., the sputtering efficiency will be approximately three times that of conventional water cooling. This results in an increased rate of thin film deposition on the substrate. Furthermore, since the energy of atoms ejected from the target is increased, the shape of the film covering the step portion of the substrate is also improved.

[Embodiments of the invention]

FIG. 1 is a sectional view showing a schematic structure of a sputtering apparatus used in an embodiment of the method of the present invention.

In the figure, reference numeral 1 denotes a sputtering chamber container, and inside this container 1, flat electrodes 2 and 3 are arranged facing each other. The upper electrode 2 is normally grounded, and the substrate 4 is placed over the electrode 21 from the substrate holder 5I. High frequency power from a high frequency power source 7 is applied to the lower electrode 3 via a matching box 6 . A target material 8 made of quartz glass (Sin) is placed on the upper surface of the electrode 3, for example, when forming a silicon oxide film.
Set up. Furthermore, a heater 9 for heating the target is buried inside the electrode 3 and is electrically insulated from the electrode 3. A current is applied to the heater 9 from an external power source 10.

In the figure, 11 indicates a gas introduction port for introducing gas into the container 1, and 12 indicates a gas exhaust port for discharging the gas within the container 1. Further, 13 indicates an insulator.

Next, the process of forming a silicon oxide film using the apparatus configured as described above will be explained. First, fill the inside of container l with 1x
After evacuation to a degree of vacuum of about 10 Torr, for example, A-r gas is introduced from the gas inlet 11.

The gas pressure inside the container 1 is maintained at 10 (mTorr). Next, the heater 9 is heated by the heater heating power source 10 to bring the surface of the target 8 to 450° C., and then the high frequency cuff is heated to 450° C., for example.
3, a discharge is generated, and the target material 8 is sputtered with Ar ions to deposit a silicon oxide film on the surface of the substrate 4. The distance between the target material 8 and the substrate 4 was set to 7.5 [6]. The deposition rate of the silicon oxide film under the above conditions was 250 [A/rnin]. In the conventional case without a heater for heating the target, the deposition rate under the same conditions as above is 80 [A/min]. That is, when the surface temperature of the target material was raised in Method 1 of this embodiment, the deposition rate became more than three times faster than in Method 1.

[Other embodiments of the invention]

The invention is not limited to the embodiments described above. For example, the method of heating the target material is not limited to the method described in the above embodiments, but may also be heated by infrared irradiation or the like. Note that a part of the electrode may be water-cooled.

Further, the target material is not limited to quartz, and may be appropriately determined depending on the type of film to be formed. Furthermore, the configuration of the device is not limited to that shown in FIG.
Any sputtering device equipped with a pair of parallel plate electrodes can be modified as appropriate, and the substrate may be heated if necessary. In addition, various modifications can be made without departing from the gist of the present invention.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a schematic configuration of a sputtering apparatus used in an embodiment of the method of the present invention. 1... Sputtering chamber container 2-3... Electrode 4...
Board 5... Board holder 6... Matching device
7...High frequency power supply 8...Target
9... Heater 10... Heater power supply 11...
・Gas inlet port 12...Gas exhaust port 13...Insulator (7317) Representative Patent Attorney Noriyuki Chika
(1 other person) Figure 1

Claims (1)

[Claims] A thin film forming method using a sputtering method in which a target material is sputtered with ions generated by electric discharge to deposit a thin film on a predetermined substrate surface, the thin film forming method comprising heating the surface of the target material to be sputtered. .