Method for manufacturing large ceramic co-fired articles

Abstract

A method of forming one or more high temperature co-fired ceramic articles, comprising the steps of: —a) forming (34) a plurality of green compacts, by a process comprising dry pressing a powder comprising ceramic and organic binder to form a green compact; b) disposing (38) a conductor or conductor precursor to at least one surface of at least one of the plurality of green compacts to form at least one patterned green compact; c) assembling the at least one patterned green compact with one or more of the plurality of green compacts or patterned green compacts or both to form a laminated assembly; d) isostatically (40) pressing the laminated assembly to form a pressed laminated assembly; e) firing (42) the pressed laminated assembly at a temperature sufficient to sinter the ceramic layers together.

Description

FIELD OF THE INVENTION[0001]The present invention relates to an improved high temperature co-fired ceramic (HTCC) processing method capable of producing large size multilayer ceramic devices. A typical application would be in the manufacture of wafer heating and electrostatic static chuck apparatus used in the manufacture of semiconductors.BACKGROUND ART[0002]Many fields of technology require large ceramic bodies having embedded electrical conductors. As a non-limitative example, in semiconductor manufacturing processes, a wafer heating or chucking apparatus may be used. In the processing of semiconductor wafers or displays, a substrate support is used to retain the substrate during a particular manufacturing process such as during chip manufacturing process. The substrate support is commonly known in the art as an electrostatic chuck (ESC) because it electrostatically clamps onto the substrate, e.g. semiconductor wafer during a manufacturing process such as in a physical vapour dep...

AI Technical Summary

Benefits of technology

The patent describes a method for manufacturing electrostatic chucks (ESCs) using a process called dry pressing. This method provides more uniform shrinkage and allows for larger components to be made. The process involves pressing ceramic powder into a uniaxial press to create a monolithic insulating ceramic body with embedded electrical conductors. The use of a conductor or conductor precursor and the application of pressure embeds the conductor within the ceramic layer. The process also allows for the creation of internal voids and channels for fluid cooling or air circulation. The thin dielectric layer is formed from a tape cast material and is optionally composed of the same green compact to prevent delamination. The method reduces manufacturing steps and ensures a reliable and efficient ESC for use in semiconductor manufacturing.

Problems solved by technology

Since semiconductor wafers are manufactured to very tight tolerances, any warping or unevenness in the clamping surface of the ESC would be highly undesirable and in an extreme case could even damage the semiconductor wafers.

Other problems encountered in the manufacture of ESCs is the difference in thermal expansion coefficient between the ceramic insulating material and the metal electrodes resulting in stress and eventual cracking within the ESC body when the ESC is operated at high temperatures or thermal cycling.

As wafer size increases, the size of heater and electrostatic chuck to handle wafers also increases, and this larger size is a challenge to the manufacturing of wafer handling devices.

Some of the current wafer heating and chucking apparatus, using glass or low temperature metal bonding, are not able to handle this high temperature requirement.

However, the cost of hot pressing is high in comparison with pressureless sintering methods; in addition, the pressure tends to break the metal mesh inside the die.

In addition, in the hot pressing method it is difficult to produce certain features such as hollow cooling channels or blind holes; therefore there is a need to develop a cost effective manufacturing method for wafer heating and chucking devices.

A problem that becomes evident in making wafer heaters and chucks is size.

Both methods have problems in producing large and thick tape.

The doctor blade method is difficult to use in producing thick tape due to the high binder and solvent content of the slurry which has to be removed in drying and firing.

The roll compaction method can produce thick tape but it is difficult to produce large sizes due to pressure limitation of the roller.

In addition, roll compaction tape shows non-uniform shrinkage during sintering.

Non-uniform shrinkage would be a major problem during the manufacturing of wafer handling devices, due to the precision dimensional control needed for wafer handling devices.

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