Patent ID: 12195402

REFERENCE NUMBERS

1, second ceramic layer;2, metal electrode layer;3, first ceramic layer;4, graphite mold base;5, graphite mold sleeve;6, pre-sintered ceramic member;7, ceramic precursor layer.

DESCRIPTION OF THE EMBODIMENTS

For better understanding of the above purposes, features and advantages of the invention, specific embodiments of the invention will be described in detail below in conjunction with the accompanying drawings.

Electrostatic chucks and heating plates used in the semiconductor manufacturing process are all multi-layer composite ceramic plates, which have a typical basic sandwich structure. The invention provides a multi-layer composite ceramic plate which is suitable for serving as an electrostatic chuck and a heating plate in the semiconductor manufacturing process, and a manufacturing method of the multi-layer composite ceramic plate.FIG.1is a schematic diagram of a basic sandwich structure of the multi-layer composite ceramic plate according to the invention, andFIG.2is a schematic diagram of the manufacturing process of the basic sandwich structure of the multi-layer composite ceramic plate according to the invention. The manufacturing process is as follows:1. A sheet-like green body with a diameter of 300 mm and a thickness of 5 mm is formed by alumina powders, subjected to spray granulation, through a cold isostatic pressing at a pressure of 200 MPa;2. The sheet-like green body with the diameter of 300 mm and the thickness of 5 mm is held at 1200° C. for 1 h in an oxidizing atmosphere, and is then pre-sintered to obtain a sheet-like pre-sintered alumina ceramic member6, wherein in this embodiment, the pre-sintering temperature is set to 1200° C.; the setting of the pre-sintering temperature is associated with the temperature of subsequent hot-pressing sintering, and generally, the pre-sintering temperature should be between 20° C. and 600° C., preferably between 100° C. and 400° C., lower than the hot-pressing sintering temperature;3. Flat grinding is carried out on surfaces of the pre-sintered alumina ceramic member6through a numerically-controlled surface grinder to make the flatness of the surfaces of the pre-sintered alumina ceramic member6not greater than 0.03 mm, not greater than 0.008 mm in an ideal condition;4. Metal tungsten paste is printed on one surface of the pre-sintered alumina ceramic member6which is subjected to finish machining, through a screen printing method to obtain a metal electrode layer2, wherein the flatness of the metal electrode layer2is not greater than 0.03 mm; in other embodiments, the metal electrode layer2may be formed on the pre-sintered ceramic member through a coating process or other film forming process; the material of the metal electrode layer is tungsten in this embodiment, but the material of the metal electrode layer is not limited to tungsten and can also be other suitable metal materials for use as metal electrodes;5. As shown inFIG.2, first, the pre-sintered alumina ceramic member6coated with the metal electrode layer2is stably placed on a graphite mold base4, and then, a graphite mold sleeve5is disposed on the graphite mold base4, with the upper surface, coated with the metal electrode layer2, of the pre-sintered alumina ceramic member6facing upwards; second, a ceramic precursor layer7is provided on the pre-sintered ceramic member6, wherein the ceramic precursor layer7is uniformly distributed alumina powders in this embodiment, and the ceramic precursor layer7may be a pre-formed unsintered sheet-like green body in other embodiments; third, hot-pressing sintering is carried out in the axial direction of the pre-sintered alumina ceramic member6, wherein in this embodiment, the sintering temperature is set to 1600° C., the holding time is 30 min, and the pressure is 20 MPa.

After hot-pressing sintering, the second ceramic layer1, formed by the pre-sintered ceramic member6, the first ceramic layer3, formed by the ceramic precursor layer7, and the metal electrode layer2corresponding to a metal electrode layer2inFIG.1, located between the first ceramic layer3and the second ceramic layer1, form a basic sandwich structure together.

In this embodiment, the ceramic precursor layer7and the pre-sintered ceramic member6are made of alumina, and alumina ceramics are obtained after the ceramic precursor layer7and the pre-sintered ceramic member6being hot-pressing sintered. In other embodiments, the ceramic precursor layer7and the pre-sintered ceramic member6may be made of one or more of alumina, zirconia, magnesium aluminate spinel, aluminum nitride, silicon nitride, and silicon carbide. In other embodiments, the first ceramic layer and the second ceramic layer are one or more of oxide ceramics such as alumina, zirconia, magnesium aluminate spinel and so on. In other embodiments, one or more of the first ceramic layer and the second ceramic layer are one or more of non-oxide ceramics such as aluminum nitride, silicon nitride, silicon carbide and so on. In other embodiments, one or both of the first ceramic layer and the second ceramic layer are composite ceramic.

As shown inFIG.1, the area of the first ceramic layer and the area of the second ceramic layer are both larger than that of the metal electrode layer, and outer edges of the first ceramic layer and the second ceramic layer are in contact with each other and form a whole by hot-pressing sintering, so that the metal electrode layer is completely packaged.

Embodiment 2

The composite ceramic plate provided by the invention may be a five-layer composite ceramic plate comprising two basic sandwich structures.FIG.3is a schematic diagram of the five-layer composite ceramic plate comprising two basic sandwich structures, andFIG.4is a schematic diagram of the manufacturing process of the five-layer composite ceramic plate comprising two sandwich structures. As shown inFIG.3andFIG.4.1. A sheet-like green body with a diameter of 300 mm and a thickness of 5 mm is formed by alumina powders, after spray granulation and cold isostatic pressing at a pressure of 200 MPa;2. The sheet-like alumina green body with the diameter of 300 mm and the thickness of 5 mm is held at 1200° C. for 1 h in an oxidizing atmosphere to obtain a sheet-like pre-sintered ceramic member6;3. Flat grinding is carried out on surfaces of the pre-sintered alumina ceramic member6through a numerically-controlled surface grinder to make the flatness of the surfaces of the pre-sintered alumina ceramic member6not greater than 0.01 mm, not greater than 0.008 mm in an ideal condition;4. Metal tungsten paste is printed on upper and lower surfaces of the pre-sintered alumina ceramic member6which is subjected to finish machining, through a screen printing method to obtain metal tungsten electrode layers2, wherein the flatness of the printed metal tungsten electrode layers is not greater than 0.01 mm;5. As shown inFIG.4, first, a graphite mold sleeve5is disposed around a graphite mold base4, and then a ceramic precursor layer7is provided on the graphite mold base4(the ceramic precursor layer7can be uniformly distributed alumina powders or a pre-formed unsintered sheet-like green body); the pre-sintered alumina ceramic member6having two sides coated with the metal electrode layers2is stably placed on the ceramic precursor layer7which is on the graphite mold base; second, another ceramic precursor layer7is provided on the pre-sintered alumina ceramic member6(the ceramic precursor layer7is uniformly distributed alumina powders or a pre-formed unsintered sheet-like green body); third, hot-pressing sintering is carried out in an axial direction of the pre-sintered alumina ceramic member6, wherein the sintering temperature is set to 1600° C., the holding time is 30 min, and the pressure is 20 MPa.

Referring toFIG.3andFIG.4, after hot-pressing sintering, a second ceramic layer1is formed by the pre-sintered alumina ceramic member6, and first ceramic layers3are respectively formed by the two ceramic precursor layers7; the upper metal electrode layer2corresponds to an upper metal electrode layer2of the five-layer composite ceramic plate shown inFIG.3and the lower metal electrode layer2corresponds to a lower metal electrode layer2of the five-layer composite ceramic plate shown inFIG.3, so that two basic sandwich structures are formed.

In this embodiment, the ceramic precursor layers and the pre-sintered ceramic member are made of alumina, and alumina ceramics are obtained after the ceramic precursor layers and the pre-sintered ceramic member being hot-pressing sintered. In other embodiments, the ceramic precursor layers and the pre-sintered ceramic member may be made of one or more of alumina, zirconia, magnesium aluminate spinel, aluminum nitride, silicon nitride, and silicon carbide. In other embodiments, the first ceramic layers and the second ceramic layer are one or more of oxide ceramic such as alumina, zirconia, magnesium aluminate spinel and so on. In other embodiments, the first ceramic layers and the second ceramic layer are one or more of non-oxide ceramics such as aluminum nitride, silicon nitride, silicon carbide and so on. In other embodiments, one or more of the first ceramic layers and the second ceramic layer are composite ceramic.

As shown inFIG.3, the area of the first ceramic layers and the area of the second ceramic layer are both larger than that of the metal electrode layers, and outer edges of every adjacent two of the first ceramic layers and the second ceramic layer are in contact with each other and form a whole through hot-pressing sintering, so that the metal electrode layers are completely packaged.

Although the invention has been disclosed above, the invention is not limited to the above description. Any skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the protection scope of the invention should be subjected to the scope defined by the claims.