JPH0657869B2 - Multi-layer thin film manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a multilayer thin film production apparatus used for producing a multilayer thin film of a material such as a metal, an oxide or a semiconductor on a substrate.

<Prior Art> As an apparatus for producing a multi-layered thin film in which two or more kinds of substances are laminated on a substrate, a vapor deposition apparatus provided with a rotary substrate holder and a plurality of sources of deposited particles as shown in FIG. A sputter vapor deposition apparatus or the like is generally used. In the figure, 2
Reference numeral 1 is a stainless steel vacuum chamber, 22 is a rotary substrate holder, 23 is a substrate, 24 is a supply source of deposited particles, 25 is a shutter, 26 is a pump, 27 is a matching box, and 28 is a target power supply.

Multilayer thin films are usually required to have uniform film thickness,
To prepare such a multilayer thin film having a uniform film thickness, the substrate 2
3 is revolved to form a layer A1 made of the material of the source 24A on the substrate when the substrate 23 comes directly above the source 24A of a certain deposited particle, and then a source other than the source 24A is supplied. A layer B1 of the material of the source 23B is formed on the layer A1 when the substrate 23 is directly above the source 24B. The method of repeating this in sequence is most commonly used.

<Problems to be Solved by the Invention> However, in such a device, although the amount of deposited particles from the target toward the substrate 23 directly above the target is the largest, the target has a particle density distribution that follows Lambert's cosine law, for example. The deposited particles are scattered in all directions above. For this reason, particles from a plurality of sources of deposited particles are partially mixed, and a substance from another source is mixed in a layer made of a certain substance. Using the sputter deposition apparatus shown in FIG. 7, a multilayer thin film in which tungsten and carbon were alternately laminated was prepared, and the amount of carbon mixed in the tungsten layer and the amount of carbon mixed in the carbon layer were measured by Auger electron spectroscopy. The results of examining the amount of tungsten mixed are shown in FIG. As shown in FIG. 8, the amount of carbon mixed into the tungsten layer is about 18%, and the amount of tungsten mixed into the carbon layer is about 4%. (Because carbon has the property of easily wrapping around, the amount of carbon that is mixed into a layer that is made of another substance is generally greater than that of tungsten.) In addition, this is improved to cover the periphery of the source of deposited particles and Only a multi-layer thin-film production system (1) with a deposition barrier with a window for scattering deposited particles and a deposition source that covers the periphery of the deposition particle supply source and is used only for scattering particles in the substrate direction. A multi-layered thin film production device that opens a window and covers the space from the supply source of deposited particles to directly above the substrate, and further opens and closes a shutter for opening and closing the deposition particle evaporation path across the side surface of this deposition prevention wall (2) As compared with the most commonly used multi-layer thin film manufacturing equipment, the amount of the above-mentioned mixed particles is considerably reduced, but carbon, which has a strong wraparound, goes out of the deposition barrier through a small gap, and this reaches the surface of the substrate. And the amount of contamination is sufficiently reduced No. An auger electron spectroscope was used to analyze a multi-layered thin film having a period length of about 10 nm, a layer thickness ratio of tungsten and carbon of 4: 6, and a period number of 20 produced by using the devices (1) and (2). FIG. 9 shows the results of examining the amounts of the constituent substances of the other layers mixed in each layer.
In the device (1), about 7% of carbon is mixed in the tungsten layer, about 0.5% of tungsten is mixed in the carbon layer, and in the device of (2) about 2% carbon in the tungsten layer. To some extent, about 0.2% of tungsten was also mixed in the carbon layer. Usually, the shutter is often circular, and is installed so that it is directly above the source of accumulated particles when the shutter is closed. However, some of the deposited particles wrap around the substrate surface from around the shutter. Therefore, the physical constants such as the optical constants of the manufactured multilayer thin film are different from the physical constants of the multilayer thin film in which the deposited particles are not mixed. For this reason, it has been difficult to obtain a multilayer thin film having physical properties such as optical properties as designed by the conventional technique.

The present invention solves the above-mentioned drawbacks of the related art, reduces the mixture of a substance forming another layer into a layer formed of a certain substance, and produces a multilayer thin film showing physical properties as designed. The purpose is to provide.

<Means for Solving Problems> The present invention provides a deposition-inhibiting wall that covers the periphery of a supply source of deposited particles in a vacuum tank of a multilayer thin-film production apparatus and opens a window for scattering scattered particles only in the substrate direction. , A multilayer thin film manufacturing apparatus having a deposition barrier with a structure in which a shutter opening / closing window is opened on the side surface of the deposition barrier, and the shutter opens and closes across the deposition barrier.
A chimney is provided between the shutter and the window for scattering the accumulated particles that is opened in the barrier, and (2) a second shutter that performs the same movement in synchronization with the shutter immediately above the chimney of the barrier. Is provided.

<Operation> A deposition barrier that covers the periphery of the deposition particle supply source in the vacuum chamber and has a window for scattering the deposition particles only in the substrate direction is provided, and a window for opening and closing the shutter is opened on the side surface of this deposition barrier. In a multilayer thin film manufacturing apparatus having a deposition barrier having a structure in which a shutter opens and closes across the deposition barrier, (1) if a chimney is provided between the upper portion of the shutter and the window for scattering accumulated particles on the deposition barrier. , The chimney prevents the deposited particles that surround the shutter, and reduces the amount of deposited particles that go out of the deposition barrier.

(2) When the second shutter is further present immediately above the chimney, most of the deposited particles also adhere to the second shutter. Therefore, these effects reduce the amount of the deposited particles reaching the surface of the substrate.

<Embodiment> FIG. 1 shows a cross section of an apparatus for producing a multilayer thin film according to an embodiment of the first invention. In the figure, 1 is a stainless steel vacuum chamber, 2 is a rotary substrate holder, 3 is a substrate, and 4 is a substrate.
Is a supply source of deposited particles, 5 is a shutter, 6 is a pump, 7
Is a matching box, 8 is a target power supply, 9 is a barrier, 10 is a window for opening and closing a shutter, 11 is a chimney, 12
Is a window for scattering accumulated particles.

The deposition barrier 9 made of stainless steel covers the periphery of the deposition particle supply source 4, and a window 12 for scattering the deposition particles is opened only in the direction of the substrate 3. Inside the deposition-inhibiting wall 9, a shutter 5 is arranged to prevent particles sputtered during pre-sputtering from reaching the substrate 3. A window 1 for scattering accumulated particles, which is open above the shutter 5 and the deposition barrier 9.
A chimney 11 is provided between the two. As a result, the accumulated particles that surround the shutter 5 are prevented by the chimney 11, and the accumulated particles that go out to the outside of the deposition preventing wall 9 can be reduced. FIG. 2 shows a perspective view of the chimney 11 as seen from below the shutter 5.

A multilayer thin film was manufactured by the multilayer thin film manufacturing apparatus having the above structure.

A Si wafer was used as the substrate 3. Ar gas was introduced into the vacuum chamber, the degree of vacuum was maintained at 10 ⁻³ Torr, and a tungsten target was sputtered at 100 W and a carbon target was sputtered at 400 W to form a multilayer thin film made of tungsten and carbon. The cycle length of the fabricated multi-layered thin film is about 10 nm
The layer thickness ratio of tungsten and carbon is 4: 6, and the number of periods is 20. FIG. 3 shows the results of analysis of the mixed state of particles other than the intended constituent substance in each layer of this multilayer thin film by using an Ager electron spectroscopy apparatus. The amount of carbon mixed in the tungsten layer is about 1% or less, the amount of tungsten mixed in the carbon layer is about 0.1% or less, and when the deposition barrier including the chimney 11 is not used. In comparison, the amount of mixed particles was reduced.

In order to investigate the optical characteristics of the produced thin film of tungsten and carbon, the X-ray reflectance was measured as an example. As shown in FIG. 4, a reflection profile calculated using the optical constants of tungsten and carbon was obtained. The measured values were obtained in which both the reflection intensity and the reflection angle were in good agreement.
This indicates that a high-quality multilayer thin film having optical characteristics close to an ideal state can be produced with a small amount of the constituent substances of other layers mixed in each layer.

FIG. 5 shows a cross section of a multilayer thin film manufacturing apparatus according to an embodiment of the second invention. In addition to the device of the first invention, the device of the second invention has a second shutter 13 directly above the chimney 11.
Is provided. The second shutter 13 performs the same movement in synchronization with the shutter 5. By providing this second shutter 13, the arrival of sputtered particles on the substrate 3 during pre-sputtering can be further prevented.

Using this apparatus, the manufacturing conditions are the same as in the first invention, the cycle length is about 10 nm, and the layer thickness ratio of tungsten to carbon is 4:
6. A multilayer thin film having a period of 20 was produced. As a result of analyzing the mixed state of the deposited particles other than the predetermined constituents in each layer of this multilayer thin film using the secondary ion mass spectrometer, the mixed amount of carbon into the tungsten layer is about 0.5%, The amount of tungsten mixed in the carbon layer is 0.05
It was about%. When the X-ray reflectance of the produced multilayer thin film made of tungsten and carbon was measured,
As shown in the figure, an actual measurement value was obtained that very well matches the reflection profile calculated using the optical constants of tungsten and carbon. This shows that the amount of the constituent substances of the other layers mixed in each layer is small, and a high-quality multilayer thin film having almost ideal optical characteristics can be produced.

<Effects of the Invention> As described above, according to the present invention, in order to produce a multilayer thin film in which two or more kinds of substances are alternately laminated on a substrate, the periphery of a supply source of deposited particles in a vacuum chamber is covered, In a multi-layer thin film manufacturing apparatus in which a deposition barrier that opens a window for scattering scattered particles only in the substrate direction is provided, a window for opening and closing a shutter is opened on the side of this deposition wall, and the shutter opens and closes across the deposition barrier.
(1) Surrounding the shutter by (1) providing a chimney between the shutter and the window for scattering accumulated particles that is opened above the deposition barrier, and (2) providing a second shutter directly above the chimney. The accumulated particles that wrap around from the chimney or the chimney and the second shutter directly above the chimney can be prevented, and the amount of accumulated particles that go out of the deposition-inhibiting wall is reduced.
Therefore, the amount of the deposited particles reaching the surface of the substrate is also reduced. For this reason, the amount of the constituent substance of the other layer mixed into a given layer is reduced. In addition, since the deposited particles that reach the surface of the substrate during the pre-sputtering are prevented, a clean substrate surface is maintained until the time of sputtering. As a result, it becomes possible to fabricate a high quality multilayer thin film having a physical constant such as an optical constant close to a designed value.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an apparatus for producing a multi-layered thin film according to an embodiment of the first invention, FIG. 2 is a perspective view of a chimney as seen from the lower surface of the shutter, and FIG. 3 is an apparatus shown in FIG. FIG. 4 is a graph showing the results of depth direction analysis of a tungsten / carbon multilayer thin film by an Auger electron spectroscope. FIG. 4 is a graph showing the X-ray reflection profile of the tungsten / carbon multilayer thin film produced by the device shown in FIG. FIG. 7 is a cross-sectional view of an apparatus for producing a multilayer thin film according to an embodiment of the second invention, FIG. 6 is a graph showing an X-ray reflection profile of a tungsten / carbon multilayer thin film produced by the apparatus shown in FIG. 5, and FIG. Is a cross-sectional view of a conventional multi-layer thin-film production apparatus, and FIG. 8 is a graph showing the depth direction analysis result of an tungsten electron-carbon multi-layer thin film produced by the apparatus shown in FIG. Figure 9 is a graph showing the tungsten / carbon multilayer thin film depth analysis by Auger electron spectroscopy apparatus manufactured in conventional multilayer thin film manufacturing apparatus having a deposition preventing walls. In the drawings, 1 ... Vacuum tank, 2 ... Rotating substrate holder, 3 ... Substrate, 4 ... Deposition source (target) of deposited particles, 5 ... Shutter, 6 ... Exhaust pump, 7 ... Matching box, 8 ... Target power supply, 9 ... an adhesion barrier, 10 ... a window for opening / closing a shutter, 11 ... a chimney, 12 ... a window for scattering accumulated particles, 13 ... a second shutter.

Claims (2)

[Claims] 1. A multi-layered thin film is formed by rotating a substrate holder part at a constant speed, and alternately depositing deposited particles from a plurality of deposited particle sources made of different substances on a substrate at regular intervals. At the time of fabrication, a deposition prevention wall was provided that covers the periphery of the deposition particle supply source in the vacuum chamber and has a window for scattering deposition particles only in the substrate direction, and the deposition particle evaporation path is opened and closed on the side surface of this deposition prevention wall. A multi-layer thin-film production apparatus having a structure in which a shutter for opening and closing is opened and closed across an adhesion barrier, wherein a cylindrical chimney is installed between the upper part of the shutter and a window for scattering accumulated particles. 2. A multi-layered thin film is formed by rotating a substrate holder part at a constant speed, and sequentially depositing deposited particles from a supply source of a plurality of deposited particles composed of different substances on a substrate at regular intervals. At the time of fabrication, a deposition prevention wall was provided that covers the periphery of the deposition particle supply source in the vacuum chamber and has a window for scattering deposition particles only in the substrate direction, and the deposition particle evaporation path is opened and closed on the side surface of this deposition prevention wall. In a multi-layered thin film manufacturing device with a structure in which a shutter for a shutter opens and closes across a deposition barrier, a cylindrical chimney is installed between the upper part of the shutter and a window for scattering accumulated particles, and the same movement is performed in synchronization with the shutter. An apparatus for producing a multi-layered thin film, characterized in that a second shutter is provided directly above the chimney on the deposition barrier.