AN APPARATUS FOR ATOMIC LAYER DEPOSITION

Abstract

The invention relates to an apparatus for subjecting a surface of a substrate to surface reactions of at least a first precursor and a second precursor according to the principles of atomic layer deposition. The apparatus comprises a reaction chamber (1) forming a reaction space (2) for receiving precursor gases reacting on the surface of the substrate. The apparatus further comprises a substrate support (3) for holding the substrate; a dielectric plate (4); and an electrode (7) coupled to a voltage source (8) to induce voltage to the electrode (7) for generating electric discharge to the reaction space (2). The dielectric plate (4) is arranged between the substrate support (3) and the electrode (7) and such that the reaction space (2) is arranged between the substrate support (3) and the dielectric plate (4).

Claims

1. An apparatus for subjecting a surface of a substrate to surface reactions of at least a first precursor and a second precursor according to the principles of atomic layer deposition, said apparatus comprising a reaction chamber forming a reaction space for receiving precursor gases reacting on the surface of the substrate, a substrate support for holding the substrate, a dielectric plate, and an electrode coupled to a voltage source to induce voltage to the electrode for generating electric discharge to the reaction space, the dielectric plate being arranged between the substrate support and the electrode so that the reaction space is arranged between the substrate support and the dielectric plate, the substrate support being movable in a vertical direction for moving the substrate between a process position in which the reaction chamber is in a closed state and a loading position in which the reaction chamber is in an open state, characterized in that the dielectric plate is movable together with the substrate support between the process position and the loading position.

2. An apparatus according to claim 1, characterized in that the reaction chamber is formed from surfaces connected to each other such that there is a bottom surface, a top surface and at least one side surface and the dielectric plate forms at least part of one of the surfaces forming the reaction chamber.

3. An apparatus according to claim 2, characterized in that the dielectric plate forms at least part of the top surface of the reaction chamber.

4. An apparatus according to any previous claim 3, characterized in that the electrode is arranged in an operational connection with the dielectric plate for generating electric discharge through the dielectric plate to the reaction space for generating plasma together with precursors supplied into the reaction space.

5. An apparatus according to claim 4, characterized in that the dielectric plate is made of glass.

6. An apparatus according to claim 1, characterized in that the electrode is arranged outside of the reaction chamber.

7. An apparatus according to claim 5, characterized in that the apparatus further comprises at least one precursor feeding channel for supplying precursor to the reaction space and at least one discharge channel for discharging precursor from the reaction space.

8. An apparatus according to claim 7, characterized in that the at least one precursor feeding channel and the at least one discharge channel are provided to the side surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In the following the invention will be described in greater detail by means of preferred embodiments with reference to the attached drawings, in which

[0014] FIG. 1 shows an embodiment of the apparatus according to the invention in a process position;

[0015] FIG. 2 shows an embodiment of the apparatus according to the invention in a loading position;

[0016] FIG. 3 shows another embodiment of the apparatus according to the invention in a process position; and

[0017] FIG. 4 shows the embodiment of the apparatus shown in FIG. 3 it a loading position.

DETAILED DESCRIPTION OF THE INVENTION

[0018] FIG. 1 shows an embodiment of the invention in which the reaction chamber 1 is closed, i.e. in a process position. The reaction chamber 1 forms the outline for the reaction space 2 in which surface reactions of at least a first precursor and a second precursor according to the principles of atomic layer deposition are subjected to a substrate 10. In this embodiment of the invention the reaction chamber 1 comprises a substrate support 3 as the bottom surface 1a of the reaction chamber 1 and a dielectric plate 4 as the top surface 1b of the reaction chamber 1. Although the figure shows that the dielectric plate 4 forms the entire top surface 1b of the reaction chamber 1, it may alternatively form only part of the top surface 1b. The electrode 7 is arranged in an operational connection with the dielectric plate 4 for generating electric discharge through the dielectric plate 4 to the reaction space 2 for generating plasma together with precursors supplied into the reaction space 2. The precursors are supplied in this embodiment of the invention from one side surface 1c of the reaction chamber 1 and discharged from the opposite side surface 1c. The apparatus comprises at least one precursor feeding channel 5 for supplying precursor to the reaction space 2 and at least one discharge channel 6 for discharging precursor from the reaction space 2. As shown in FIG. 1 the feeding channel 5 and the discharge channel 6 are arranged such that the output face of the channels 5, 6 are on the side surfaces 1c of the reaction chamber 1. In another embodiment of the invention the precursor feeding channel 5 and the discharge channel 6 may be arranged to extend such that the output face of the precursor feeding channel 5 is arranged to the top surface 1b of the reaction chamber land the output face of the discharge channel may be arranged on both of the side surfaces of the reaction chamber 1 or to the other side surface of the reaction chamber 1 or such that the precursors are discharged from the side surfaces of the reaction chamber 1 and further pumped under the bottom surface 1a outside of the reaction chamber 1. The electrode 7 is arranged outside the reaction chamber 1 and coupled to a voltage source 8 to induce voltage to the electrode 7 for generating electric discharge to the reaction space 2 for creating plasma together with precursors. The voltage source 8 may be arranged further away from the electrode 7 or it may be close to the electrode 7. As the electrode 7 is arranged outside the reaction chamber 1 also the electrode match is arranged outside the reaction chamber 1. In other words the reaction chamber 1 is formed from a bottom surface 1a, a top surface 1b and at least one side surface 1c for forming a reaction space 2 in which the surface reactions of a substrate 10 are arranged to happen. The electrode 7 is arranged outside of the reaction space 2 such that between the electrode 7 and the reaction space 2 is a dielectric plate 4. The electrode 7 is coupled to a voltage source which is preferably an RE-generator.

[0019] The substrate support 3 preferably comprises a movable susceptor having a support part 3a for supporting the substrate and a pedestal part 3b for moving the substrate between the process position and the loading position. The movement of the pedestal part 3b is preferably vertical. In other words the substrate support 3 can be moved to unload the processed substrate and to reload a new substrate.

[0020] FIG. 2 shows the reaction chamber 1 in an open state, i.e. in a loading position. In this figure the substrate 10 to be processed will be loaded to the substrate support 3 when the pedestal part 3b has moved together with the support part 3b such that the reaction chamber 1 is open and there is space to load the substrate 10 to the substrate support 3. The dielectric plate 4 forms at least part of the top surface 1b of the reaction chamber 1. The dielectric plate 4 can be arranged as a fixed part of the apparatus or alternatively as a removable part of the apparatus. When being arranged as a removable part the dielectric plate 4 is arranged such that it can be taken from the apparatus for cleaning purposes or other maintenance and then put back again without disassembling the whole apparatus or most of the apparatus but for example by loosening the connection between the dielectric plate 4 and the structure surrounding the dielectric plate 4.

[0021] In another embodiment of the apparatus the dielectric plate 4 is pressed against a structure surrounding the dielectric plate with the help of a movable support and the dielectric plate 4 can be moved together with the movable support for removal from the apparatus. In this embodiment of the invention the dielectric plate 4 forms at least part of the top surface 1b of the reaction chamber 1. Alternatively the dielectric plate 4 can be arranged to the bottom surface 1a of the reaction chamber 1 in which case the reaction chamber is preferably opened somewhere else than from the bottom surface 1a, for example from the top surface 1b. The dielectric plate 4 is preferably made of glass, but it can be from other dielectric material such as plastic.

[0022] In an embodiment of the invention in which the substrate support 3 is movable in a vertical direction for moving the substrate 1 between a process position in which the reaction chamber 1 is in a closed state and a loading position in which the reaction chamber 1 is in an open state the dielectric plate 4 is also made as movable part. The dielectric plate 4 can be movable together with the substrate support between the process position and the loading position or it may have an own support structure which is movable or alternatively if a mask frame is used in the coating process and has its own movable mask alignment supports then the dielectric plate 4 can move together with the mask alignment supports.

[0023] FIG. 3 shows an embodiment of the invention in which the apparatus comprises lifters 11 for moving the dielectric plate 4 in a vertical direction for removing said dielectric plate 4 from the apparatus to be cleaned or replaced. In other words, the dielectric plate 4 is arranged removably to the apparatus such that it can be removed from the apparatus without disassembling the whole apparatus. The FIG. 3 shows the apparatus in a process position in which the reaction chamber 2 is closed so that the substrate 10 can be processed. In this embodiment the feeding channel 5 and the discharge channel 6 are arranged such that the output face of the channels 5, 6 are on the side surfaces 1c of the reaction chamber 1 and the dielectric plate 4 forms the top surface 1b of the reaction chamber 1. The bottom surface 1a of the reaction chamber 1 is formed with the substrate support 3 which comprises the support part 3a for supporting the substrate and the pedestal part 3b for moving the substrate between the process position and the loading position. The output face of the feeding channel 5 and the discharge channel 6 are arranged such that they are movable in vertical direction together with the dielectric plate 4. The movement of the dielectric plate 4 is arranged with lifters 11 supporting the output face part of the channels 5, 6.

[0024] FIG. 4 shows the apparatus shown in FIG. 3 in a loading position in which the pedestal 3b has moved the substrate 10 in the substrate support 3a downwards and the lifters 11 have moved part of the channels 5, 6 and the dielectric plate 4 downwards such that the dielectric plate 4 can be removed from the apparatus. This is just one example of how to remove the dielectric plate 4 from the apparatus.

[0025] It will be obvious to a person skilled in the art that, as the technology advances, the inventive concept can be implemented in various ways. The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.