Loading patent…
AssigneeASM Japan K.K.
InventorsNaoto Tsuji, Ryo Kawaguchi, Atsuki Fukazawa, Rei Tanaka
Estimating the term…
A plasma CVD apparatus includes a vacuum chamber, a showerhead, and a susceptor characterized in that an insulation ring is placed and embedded in a peripheral portion of the susceptor to increase the electrically effective distance between the showerhead and the susceptor, both of which functions as electrodes.
A plasma CVD apparatus comprising a vacuum chamber comprising a showerhead and a susceptor, between which electric voltage is applied to generate a plasma, said susceptor comprising an inner portion and a peripheral portion, said peripheral portion being in the vicinity of a periphery of a substrate to be placed on the susceptor, wherein an electrically effective distance between the showerhead and the susceptor is greater in the periphery portion than in the inner portion.
A susceptor adapted to be installed in a vacuum chamber of a plasma CVD apparatus, comprising an inner portion and a peripheral portion, said peripheral portion being in the vicinity of a periphery of a substrate to be placed on the susceptor, said peripheral portion being configured to have a greater electrically effective distance from a showerhead provided in the vacuum chamber than that of the inner portion.
A plasma CVD apparatus comprising a vacuum chamber, a showerhead which is disposed inside said vacuum chamber, and a susceptor for placing thereon a workpiece to be processed, said susceptor being disposed parallel to and opposing to said showerhead and being characterizable in that an insulation ring is embedded in a peripheral portion of said susceptor.
Dependencies are inferred from the claim text.
Drawings are temporarily unavailable. Open the PDF at USPTO
Backward citations are indexed for grants only.
Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources: radio frequency generated…
Characterised by the method used for supporting substrates in the reaction chamber: rigid and flat substrates, e.g. plates or discs
The substrate being supported substantially horizontally: devices at or outside the perimeter of the substrate support, e.g. clamping rings, shrouds
Using internal electrodes: flat-bed apparatus
Term end not estimated
1. Field of the Invention
The present invention relates to a plasma CVD apparatus for forming a thin film on a semiconductor wafer, and it particularly relates to a plasma CVD apparatus characterized by its susceptor structures.
2. Description of the Related Art
These and other features of this invention will now be described with reference to the drawings of preferred embodiments which are intended to illustrate and not to limit the invention.
FIG. 1 is a schematic view of a conventional plasma CVD apparatus.
FIG. 2 is a schematic view of a preferred embodiment of the CVD apparatus according to the present invention.
Explanation of symbols used is as follows: 2: Heater; 4: Semiconductor wafer; 5: Source gas inlet port; 6: Reaction chamber; 7: Primary radio-frequency power source; 8: Secondary radio-frequency power source; 9: Showerhead; 10: Exhaust port; 11: Grounding; 20: Plasma CVD apparatus; 21: Susceptor; 22: Insulation ring.
As explained above, in an embodiment, a plasma CVD apparatus comprises a vacuum chamber comprising a showerhead and a susceptor, between which electric voltage is applied to generate a plasma, said susceptor comprising an inner portion and a peripheral portion, said peripheral portion being in the vicinity of a periphery of a substrate to be placed on the susceptor, wherein an electrically effective distance between the showerhead and the susceptor is greater in the periphery portion than in the inner portion. In the above, the peripheral portion of the susceptor may be a circularly formed recess to increase the electrically effective distance in the peripheral portion, or may be composed of a dielectric material to increase the electrically effective distance in the peripheral portion.
When using a low dielectric constant material, the material of the peripheral portion may have a dielectric constant (∈) of about 10 or lower, including 9, 8, 7, 6, 5, 4, 3, 2, and a range including any two of the foregoing. If a circular recess is used, the dielectric constant is about one as explained below. Any suitable material can be used for the peripheral portion and may be selected from the group consisting of metal oxides and metal nitrides. Preferably, the material of the peripheral portion may be an aluminum oxide or nitride, or a magnesium oxide or nitride, such as alumina (Al2O3, ∈=about 8), aluminum nitride (AlN, ∈=about 8.6-8.7), or magnesium oxide (MgO, ∈=about 6 to about 8). The dielectric constant varies especially in the case of sintered bodies such as AlN or MgO. The material of the inner portion of the susceptor may be aluminum, for example.