JPS6276726A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To improve an oxidizing rate and to prevent a plasma oxidizing unit from deteriorating or the consumption of power to no avail by supplying power of a power source in a DC manner to a magnetron. CONSTITUTION:If power supplies from a magnetron power source 1 to a magnetron 2 is the same, the oxidizing rate increases as the duty is larger, and when DC is supplied, the maximum oxidizing rate is obtained. Since the oxidizing rate can be raised if the power supply to the magnetron is in a DC manner, it can prevent a plasma oxidizing unit from deteriorating due to the increase in the improper peak current like in the conventional one, an arc discharge from occurring and the consumption of power to no avail from occurring.

Description

[Detailed Description of the Invention] [Summary] A method for manufacturing a semiconductor device that performs plasma oxidation using microwaves generated by a magnetron, which improves the oxidation rate by supplying DC power to the magnetron. Plasma oxide film can prevent this deterioration and wasteful power consumption.

[Industrial application field]

The present invention relates to a method of manufacturing a semiconductor device, and more specifically, to a method of manufacturing a semiconductor device in which plasma oxidation is performed using microwaves generated by a magnetron.

[Conventional technology]

The plasma oxidation method uses microwaves generated by a magnetron to turn oxygen-containing gas into plasma, thereby performing the desired oxidation, and it is becoming more widely used today because it can form an oxide film at low temperatures. be.

Figure 2 is a configuration diagram of an apparatus that performs plasma oxidation using microwaves, where l is the magnetron power supply and magnetron 2
Supplies power to 2 is a magnetron that generates microwaves using the power supplied from the magnetron power supply 1, and 3 is a waveguide that propagates the microwaves.

4 is a microwave transmission window that partitions the processing chamber 5 and the waveguide 3; 6 is a wafer a stand; and 7 is a wafer to be oxidized.

Further, 8 is a gas inlet for introducing oxidizing gas, and 9 is a gas outlet for discharging the gas after treatment.

According to the conventional example, from magnetron electric gi to magnetron 2
Electric power is supplied to the AC using half-wave rectification or after-wave rectification (see FIGS. 3(a) to 3(C)).

Therefore, according to the conventional method, when increasing the oxidation rate to speed up the processing, the peak current of half-wave rectification or full-wave rectification is increased to increase the power supplied to the magnetron 2.

[Problem that the invention seeks to solve]

However, if the peak current is increased unduly, this is not only undesirable as it causes arc discharge, etc., but also causes shortening of the life of the magnetron power supply 1.

Furthermore, if the peak current is made too high, there is a risk that discharge will occur at places with poor contact within the waveguide or at protrusions in the vacuum processing chamber, and the magnetron itself will also be easily damaged.

The present invention was created in view of the problems of the prior art, and an object of the present invention is to provide a method for manufacturing a semiconductor device with good processing efficiency, in which oxidation is performed by plasma generated by microwaves generated from a magnetron.

[Means for solving problems]

The present invention is a method for manufacturing a semiconductor device in which a gas containing oxygen is turned into plasma by microwaves generated by a magnetron, thereby performing plasma oxidation, wherein the power supply from the magnetron power supply to the magnetron is DC. .

[Effect]

Power is supplied from the magnetron power source to the magnetron in a direct current manner, making it possible to obtain the highest oxidation rate without changing the magnitude of the supplied power. Therefore,
Furthermore, it is possible to prevent deterioration of the plasma oxidation device and the occurrence of arc discharge due to an unreasonable increase in peak current, and to prevent wasteful power consumption.

〔Example〕

Next, an embodiment of the present invention will be described.0 The apparatus used in the embodiment method of the present invention is basically the same as the apparatus shown in FIG. The pulse width of the input wave can be varied while keeping the power constant.

It is also possible to output direct current.

Using the apparatus according to the embodiment of the present invention shown in FIG. 1, the inventor performed plasma oxidation while keeping the power supplied to the magnetron 2 constant while changing the duty (pulse width) of the supplied wave. The second figure is a diagram showing the results, in which the horizontal axis shows the duty (%) of the supplied wave, and the vertical axis shows the formed oxide film.

However, the thickness of the oxide film is standardized by the duty = 100%, that is, the film thickness formed when the supplied wave is DC.As shown in Figure 2, the power supplied from the magnetron power supply 1 to the magnetron 2 are the same, the larger the duty, the higher the oxidation rate.

In particular, by using direct current, it is possible to obtain the highest oxidation rate.

As described above, according to the embodiment of the present invention, it is possible to increase the oxidation rate by supplying direct current to the magnetron, thereby preventing the deterioration of the device and the occurrence of arc discharge as in the conventional example. This makes it possible to prevent unnecessary power consumption.

〔Effect of the invention〕

As described above, according to the present invention, by supplying power from the magnetron power source to the magnetron in a direct current manner, it is possible to obtain a high oxidation rate without increasing the peak value of the supplied current. Moreover, this makes it possible to prevent arc discharge, deterioration of the device, and wasteful power consumption.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of a plasma oxidation apparatus, and Figure 2 is a diagram explaining an embodiment of the present invention, and shows the relationship between the duty of the current wave supplied to the magnetron and the thickness of the oxide film formed by plasma oxidation. FIG. FIG. 3 is a diagram showing a current waveform when power is supplied from a magnetron power source to a magnetron according to a conventional example. l... Magnetron power supply 2... Magnetron 3... Waveguide 5... Processing chamber 6... Wafer a stand 7... Wafer 8... Gas inlet 9... Gas outlet ′・ ゛、Representative Patent Attorney Sada Igeta:～. 'j-7:-2' Betei (%) Main house May 1st 1st day of the t-horizon L-[0 Fig. 2

Claims (1)

[Claims] A method for manufacturing a semiconductor device in which oxygen-containing gas is turned into plasma by microwaves generated by a magnetron, thereby performing plasma oxidation, characterized in that power supply from a magnetron power source to the magnetron is direct current. Method.