JPS61133376A - Method and device for forming thin film - Google Patents

Abstract

PURPOSE:To form a thin film having excellent adhesiveness and a specified compsn. ratio by constituting a titled method and device of the 1st stage for depositing a vapor deposition material by evaporation on a sample, the 2nd stage for irradiating ions of high energy to the sample, the 3rd stage for depositing the vapor deposition material by evaporation on the sample and the 4th stage for irradiating ions of low energy to the sample. CONSTITUTION:The sample 4a is cleaned by a high energy ion source 8A and a rotary holder 10 is rotated to deposit an evaporating material by evaporation from a vapor source 6 on the sample to form the thin film F1 thereon in the 1st stage. The rotary holder 10 is rotated and the ions are irradiated to the sample from the high energy ion source 8A to form a mixing layer M on the sample in the 2nd stage. The rotary holder 10 is rotated and the vapor deposition material is deposited by evaporation from the vapor source 6 on the thin film F1 to form a thin film F2 thereon in the 3rd stage. The rotary holder 10 is rotated and the ions are irradiated from the low energy ion source 8B to the sample to form the thin film F2 having the desired element compsn. in the 4th stage.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a thin film forming method and an apparatus therefor, in which an evaporated substance is deposited on a sample in vacuum and the sample is irradiated with ions.

[Conventional technology]

FIG. 3 is a schematic diagram showing an apparatus used in a conventional thin film forming method. Attach the sample 4 to the fixed holder 2,
In a vacuum, an evaporative substance (for example, Ti (titanium)) is deposited on the sample 4 from the evaporation source 6 below, and the ion source 8
ions of a predetermined energy (for example, N"(
A thin film is formed on the surface of the sample 4 by irradiating nitrogen ions) alternately or simultaneously with vapor deposition.

[Problem that the invention seeks to solve]

In the thin film forming method described above, it is better to have a higher ion energy (for example, about 40 KeV) in order to strengthen the interface between the sample and the deposited material, but conversely,
There is a contradiction that in order to increase (deposit) a thin film, the lower the ion energy (for example, around IKeV), the better. The reason for this is that when the ion energy is high, a mixing layer between the sample, the deposited substance, and the ions is formed thickly, making the interface strong, while when the ion energy is low, sputtering is small and the elements on the sample surface are This is because a thin film having a constant composition ratio is formed.

If the energy is high, a thin film will be formed on the surface layer (a little deeper than the surface) rather than on the surface.

Therefore, an object of the present invention is to provide a thin film forming method and an apparatus therefor that can solve the above-mentioned contradiction.

[Means for solving problems]

The thin film forming method of the present invention includes a first step of depositing an evaporation substance onto a sample, a second step of irradiating the sample with high-energy ions after the first step, and a second step of irradiating the sample with high-energy ions after the second step. The method includes a third step of depositing an evaporated substance, and a fourth step of irradiating the sample with low-energy ions after the third step.

Further, the thin film forming apparatus of the present invention includes a rotary holder that rotates with a plurality of samples attached to the outside, an evaporation source that sequentially evaporates an evaporation substance onto the samples on the rotary holder from a first direction, and a evaporation source that sequentially evaporates an evaporation substance onto the samples on the rotary holder from a first direction. The apparatus includes a high-energy ion source that sequentially irradiates the sample on the rotating holder with high-energy ions, and a low-energy ion source that sequentially irradiates the sample on the rotating holder with low-energy ions from a third direction.

[Effect]

In this thin film forming method, a deposition substance is deposited on the surface of the sample in the first step, and a thick mixing layer of the sample, deposition substance, and ions is formed in the second step, so that the interface between the sample and the deposition substance is formed. The material becomes strong, and in the third step, a deposition material is deposited thereon, and in the fourth step, a thick thin film having a desired elemental composition is formed on the sample surface.

Further, in this thin film forming apparatus, the deposition of a vapor deposition substance, high-energy ion irradiation, and low-energy ion irradiation are performed alternately and continuously on each sample on the rotating holder.

〔Example〕

FIG. 1 shows an embodiment of the thin film forming apparatus of the present invention.

FIG. The rotary holder 10 has a rectangular shape, for example, and has samples 4a and 4 on its four outer sides.
b, 4c, and 4d are attached, and rotate, for example, in the direction of arrow R in the figure. In addition, the rotating holder 10 is equipped with a cooling mechanism (not shown), which allows the samples 4a-4b
Cool 14 cs 4 d. An evaporation source 6 is provided below the rotary holder 10, and the evaporation source 6 is used to sequentially deposit an evaporation substance onto the samples 4a14b and 4C14d from below. For example, a high-energy ion source 8A is provided above the rotating holder 10, and the samples 4a, 4b, and 4C14d are sequentially irradiated with high-energy ions from above. Furthermore, a low-energy ion source 8B, for example, is provided on the side of the rotary holder 10, and the samples 4a54b, 4c, and 4d are sequentially irradiated with low-energy ions from the side. The energy of the ions extracted from the high-energy ion source 8A is, for example, about 40 KeV, and the energy of the ions extracted from the low-energy ion source 8B is, for example, about IKeV.

In this invention, the reason why two types of ion sources, high energy ion source 8A and low energy ion source 8B, are provided is as follows. In other words, there is a limit to the voltage control range of one ion source, which is at most 10% to 100% (for example, 4%
The reason for this is that if the extraction voltage is too small or too large, the divergence of the ion beam will increase and the proportion of the ion beam hitting the electrodes in the extraction section will increase, resulting in a significant decrease in the beam amount. .Also, even if this is not the case, the beam amount is proportional to the voltage, so if you simply lower the voltage, the beam amount (i.e., the irradiation capacity) will decrease in proportion to the voltage, and irradiation will take longer. This invention improves the efficiency of thin film formation by providing a high energy ion source 8A and a low energy ion source 8B.

Next, with reference to FIG. 2, a method for forming a thin film using the apparatus shown in FIG. 1 will be explained. However, in FIG. 2, the thin film portion is shown enlarged.

(1) First, a sample (for example, sample 4a) is cleaned using the high-energy ion source 8A (step (a) in FIG. 2). However, this step may be omitted.

■Next, rotate the rotary holder 10 and use the evaporation source 6 to
Deposit about 300A of evaporated material on a (step shown in Figure 2)
b)). As a result, a thin film Fl is formed on the surface of the sample 4a.

Next, the rotary holder 10 is rotated and the sample 4a is irradiated with ions of about 40K13V from the high-energy ion source 8A (step (C) in FIG. 2). As a result, a thick mixing layer M of the sample, vapor deposited substance, and ions is formed near the surface of the sample 4a, and the interface between the sample and the vapor deposited substance is strengthened. Note that the dotted line in the diagram showing step (c) in FIG. 2 indicates the original surface of the sample.

■Next, rotate the rotary holder 10 to evaporate [sample 4 at 6].
An evaporation material is deposited to a suitable thickness on the film F1 (step (d) in FIG. 2), thereby forming a thin film F2 on the thin film F1.

Next, the rotary holder 10 is rotated and the sample 4a is irradiated with ions of approximately IKeV using the low energy ion source 8B (step (e) in FIG. 2). As a result, a thin film F2 having a desired elemental composition is formed on the surface of the sample 4a.

Thin film formation may be completed at 0 or more, but if necessary,
Even if the rotary holder 10 is continuously rotated, the evaporation source 6 and the low-energy ion source 8B are continuously operated, and the sample 4a is alternately irradiated with Mi and low-energy ion irradiation an appropriate number of times. good.

At this time, the high energy ion source 8A is inactive.

As described above, in this invention, the sample is
(When forming a thin film, an evaporation source 6 and a high-energy ion source 8A are used together, thereby forming a mixing layer to strengthen the interface between the sample and the thin film. Then, a thin film is formed on the sample. When increasing the thickness of the sample, the evaporation source 6 and low energy ion source 8B are used together.In this case, since thin film formation is performed with low energy, the temperature rise of the sample can be suppressed to a low level. A thin film having a constant elemental composition ratio (for example, the ratio of Ti to N of TiN formed when the evaporated material is Ti and the ion is N6 is constant) can be formed on the extreme surface of the sample.Furthermore, Sputtering rate is reduced due to low energy.

Furthermore, as shown in FIG. 1, since a plurality of samples are attached to the holder 10 and the holder 10 is rotated, high-energy ion irradiation and low-energy ion irradiation are alternately applied to the plurality of samples. Moreover, it can be performed continuously. Therefore, the efficiency of thin film formation is very high. Moreover, if the holder 10 is provided with a cooling mechanism, the sample is cooled when it is not exposed to ions or evaporated substances, and the physical properties of the sample are prevented from changing due to high temperatures.

〔Effect of the invention〕

As explained above, according to the thin film forming method of the present invention,
In conjunction with vapor deposition, it is possible to achieve both high-energy ion irradiation and low-energy ion irradiation, thereby strengthening the interface between the sample and the deposited material and forming a thick thin film with a constant elemental composition on the sample surface. I can do it.

Furthermore, according to the thin film forming apparatus of the present invention, two types of ion sources, a high-energy ion source and a low-energy ion source, are provided, and since a plurality of samples are attached to the rotating holder, the interface between the sample and the deposited material is strong. Moreover, a thin film having a constant elemental composition ratio on the sample surface can be efficiently formed in a short time.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the thin film forming apparatus of the present invention. FIG. 2 is a process diagram showing an embodiment of the thin film forming method of the present invention. FIG. 3 is a schematic diagram showing an apparatus used in a conventional thin film forming method.

Claims (2)

[Claims] (1) In a thin film forming method in which an evaporative substance is deposited on a sample in a vacuum and ions are irradiated onto the sample, a first step of depositing an evaporative substance onto the sample, and after the first step, a second step in which the sample is irradiated with high-energy ions; a third step in which an evaporated substance is deposited on the sample after the second step; and a third step in which the sample is irradiated with low-energy ions after the third step. A method for forming a thin film, comprising the steps of step 4. (2) In a thin film forming apparatus equipped with an evaporation source that deposits an evaporation substance onto a sample in vacuum and an ion source that irradiates the sample with ions, a rotary holder that rotates with multiple samples attached to the outside. an evaporation source that sequentially deposits an evaporated substance onto the sample on the rotating holder from a first direction; a high-energy ion source that sequentially irradiates the sample on the rotating holder with high-energy ions from a second direction; 1. A thin film forming apparatus comprising: a low energy ion source that sequentially irradiates a sample on a rotating holder with low energy ions from the direction of .