JPS62199768A - Thin film forming device - Google Patents

Abstract

PURPOSE:To deposit thin films on a substrate having ruggedness on the surface with good coverage of steps by providing a shielding plate between a sputtering target and the substrate and shielding the advance of the sputtering particles from the regions except the region where the target is perspective in the recesses of the ruggedness on the substrate surface. CONSTITUTION:The shielding plate 104 is installed between the sputtering target 102 provided in a vacuum vessel 101 and the substrate on a substrate supporting base 103 and is electrically connected to the vacuum vessel 101. The shielding plate 104 is constituted of a plate 201 bored with plural pieces of circular holes and a plate 202 which closes the other holes at the time of using one hole. A revolving shaft 203 is attached only to the plate 201. The advance of the sputtering particles from the regions except the region where the target 102 is perspective is thus shielded by the recesses of the rugged parts on the surface of the substrate and the region where the target 102 is perspective from the substrate is made circularly symmetrically variable, by which the incident distribution of the deposited spattering particles on the substrate is always optimized according to the ruggedness of the substrate surface.

Description

[Detailed Description of the Invention] In order to accumulate sputtered particles, the direction of the sputtered particles flying onto the substrate is made as random as possible, and the particles deposited on the surface wrap around the substrate, thereby improving step coverage. Ta. In order to make the flying direction of the sputtered particles random, methods have been implemented in facing type sputter thin film forming apparatuses, such as making the sputter target larger than the substrate or rotating the substrate during thin film formation. More recently, a bias sputtering method has been developed in which power is also applied to the substrate side during film formation to simultaneously perform film deposition and sputter etching of the portions of the substrate that protrude from the shoulders of the convex and convex portions in the horizontal direction of the substrate. A thin film is also deposited on a substrate having an uneven surface with good step coverage or with a flat surface.

(The problem that the invention is trying to solve) However,
In order to deposit a thin film with good step coverage on a substrate with an uneven surface, the method of making the sputtering target larger than the substrate and scattering the direction of sputtered particles toward the substrate is based on the aspect of the surface unevenness. It is effective when the ratio (depth 7 width) is small, but when the aspect ratio of unevenness becomes large, A.C.Adams (A, C, Ada
Solid State Technology (So
lid State'J"technology) Magazine, 1
As shown on pages 135 to 139 of the April 1983 issue, among the sputtered particles incident on the substrate, there are many components that are significantly tilted from the vertical direction of the substrate, so that the deposited film on the shoulder of the convex portion is Since the deposited film protrudes in the horizontal direction and closes the upper part of the recess before the deposited film fills the inside of the recess, there is a region in the recess where the thin film is not deposited, which has the disadvantage that the inside of the recess cannot be filled more densely with the thin film. Furthermore, Mogami et al. Proceedings of the 1985 Second International IEEP ILSI Multilevel Interconnection Conference (Proceeding 5econd)
.

International IEEE VLSI M
ultilevel interconnection
Conference), pp. 17-23 (1985), even when forming a thin film by bias sputtering, if the surface irregularities become larger than a certain level, the thin film will be deposited in the recesses as in the case of normal sputtering. There was a problem that some areas were left unused.

An object of the present invention is to solve the problems of conventional thin film forming apparatuses using sputtering or bias sputtering as described above, and to solve the problems of thin film forming apparatuses using conventional sputtering or bias sputtering. The object of the present invention is to provide a new thin film forming apparatus that can deposit well.

(Means for Solving the Problems) According to the present invention, sputter particles from a region other than the region where the sputter target is expected are formed between the sputter target and the substrate disposed facing each other, at least from the concave portion of the unevenness of the substrate surface. A thin film forming apparatus by sputtering is obtained, which is characterized by providing a shielding plate for shielding the ingress.

(Function) In the present invention, the problems associated with conventional thin film forming apparatuses using sputtering or bias sputtering are solved by using the above-mentioned thin film forming apparatus.

In thin film forming equipment using conventional sputtering or bias sputtering, depending on the degree of surface irregularity,
Changing the distribution of the flying direction of sputtered particles toward the substrate, or shielding sputtered particles that are incident on the substrate from a direction that is greatly tilted from the direction perpendicular to the substrate when the surface of the substrate is highly uneven, can be done by changing the structure of the equipment. This was not considered above and could not be implemented. In the thin film forming apparatus according to the present invention, there is provided a space between the sputter target and the substrate, at least an area where the intrusion of sputter particles from a region other than the area where the sputter target is expected from the concave portion of the unevenness of the substrate surface is blocked, and an area where the sputter target is expected from the substrate. By installing a shielding plate that changes circularly symmetrically,
Depending on the degree of surface unevenness or the shape of the film deposited, the distribution of sputtered particles toward the substrate can be changed at any time during film deposition, or some of the sputtered particles can be shielded from the substrate. Therefore, the incident distribution of deposited sputtered particles onto the substrate can be constantly optimized depending on the irregularities of the substrate surface. Therefore, in the case of irregularities with a high aspect ratio, the shielding plate can be made narrower to shield sputtered particles that are largely tilted from the vertical direction of the substrate, and to suppress horizontal protrusion at the shoulders of the convex portions.

(Example) Examples of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the thin film forming apparatus of this invention has the following features:
Sputter target 102 provided in vacuum chamber 101
, substrate support stand 103 , shielding plate 104 and vacuum chamber 101
gas introduction mechanism 105 and exhaust system 106 of the vacuum chamber 101
It consists of The sputter target 102 is insulated from the vacuum chamber 101 and connected to a high frequency power source 107 and a matching circuit 1.
It is connected to 08. The substrate support stand 103 is connected to the vacuum chamber 1
01, high frequency power supply 107 and matching circuit 10
8 is connected. The shielding plate 104 is electrically connected to the vacuum chamber 101. A shielding plate 104 is installed between the sputter target and the substrate. Here, the shielding plate 104
As shown in FIG. 2, the shielding plate 20 is composed of a plate 201 in which several circular holes are made and a plate 202 that closes the other holes when one hole is used.
It is sufficient to add only one shielding plate rotating shaft 203.

Alternatively, as shown in FIG. 3, it is composed of several plates 301 with holes of different diameters and support shafts 302 of these plates, and any one of the plates 301 is attached to the substrate. A rotation mechanism installed above may be added. Furthermore, as shown in FIG. 4, N (N=10 to 20) U-shaped plates 401, a rotating support 402 having guide grooves for the U-shaped plates, and a rotating support 402 provided above or below the U-shaped plates 401, A non-rotating support stand 403 for a U-shaped plate may be added, and a rotation mechanism for the support stand 402 may be added thereto. The U-shaped plates 401 are arranged in the same rotation direction so as to overlap each other. A pin 404 at one end of the U-shaped plate 401 is fixed to the non-rotating support base 403, and a pin 405 provided at the other end is fitted into a guide groove 406 provided in the support base 402 having the guide groove. There is. As shown in FIG. 3, it rotates around the guide groove 404 and moves from the position shown by the solid line to the position shown by the broken line. By arranging N U-shaped plates and rotating the support base 402 having the guide groove, the diameter of the approximately circular hole surrounded by the N U-shaped plates changes. As a result, the size of the hole formed by the shielding plate can be changed circularly symmetrically.

In the above embodiment, the number of holes in the shield plate used at one time is 1.
However, the shield plate does not necessarily have to have one hole, and may have a structure in which a plurality of holes are provided in circular symmetry with respect to the substrate.

In the case of a shielding plate with this structure, the structure of each plate or hole is similar to the structure shown in Fig. 2, Fig. 3, or Fig. 4, and the area where the sputter target is viewed from the substrate can be varied in a circularly symmetrical manner. shall be taken as a thing. Furthermore, in order to ensure uniformity in the thickness of the deposited film on the substrate, a mechanism may be added that rotates the entire shielding plate having the structure in which the plurality of holes are provided.

(Effects of the Invention) As explained above, according to the present invention, in a thin film forming apparatus using a sputtering method, it is possible to change the flying direction distribution of sputtered particles with respect to a substrate at any time during film deposition, A part of the sputtered particles can be shielded, and the incident distribution of the deposited sputtered particles onto the substrate can be constantly optimized.

As a result, compared to a conventional thin film forming apparatus using a sputtering method, it is possible to densely fill the inside of a recess with a deposited film even for a substrate with a more uneven surface.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the thin film forming apparatus of the present invention, FIG.
4 and 4 are schematic diagrams of a shielding plate that is part of the device configuration of the present invention. 101... Vacuum chamber 102... Sputter target 103... Substrate support stand 104...
... Shielding plate 105 ... Gas inlet 106 - Curved exhaust system 107 ... High frequency power supply 108 ...
Matching circuit 201... Shielding plate 202... Shutter plate for shielding plate 203... Shielding plate rotation axis
301... Shield plate 302... Shield plate support shaft 401... U-shaped plate 402... Rotating support base 403... Non-rotating support base 404
...Pin 405 of a U-shaped plate fixed to a non-rotating support base...Pin 406 of a U-shaped plate fitted into a guide groove...Guide provided on a rotating support base Groove Figure 1 Figure 2 Invitation 3

Claims (1)

[Claims] A thin film produced by sputtering, characterized in that a shielding plate is provided between a sputtering target and a substrate disposed to face each other, for shielding sputtered particles from entering from at least an area other than the area where the sputtering target is expected from concave portions of the unevenness of the substrate surface. Forming device.