Method for making a high temperature resistant silicon alloy joint for the joining of ceramics and devices using same
A method for the joining of ceramic pieces with a hermetically sealed joint comprising brazing a layer of joining material between the two pieces. The ceramic pieces may be aluminum nitride or other ceramics, and the pieces may be brazed with a silicon and an alloying element under controlled atmosphere. The joint material is adapted to later withstand both the environments within a process chamber during substrate processing, and the oxygenated atmosphere which may be seen within the interior of a heater or electrostatic chuck.
1. A method for the joining of ceramic materials, said method comprising the steps of:
placing a brazing element in a joint interface area between the first interface surface of a first ceramic piece and the first interface area of a second ceramic piece to create a joining pre-assembly, said brazing element comprising silicon and germanium, wherein germanium comprises 2 to 70 mole percent of said brazing element, and wherein the remainder of said brazing element is silicon, wherein said first ceramic piece comprises aluminum nitride, and wherein said second ceramic piece comprises aluminum nitride;
placing the joining pre-assembly into a process chamber;
removing oxygen from said process chamber prior to the heating step, wherein the step of removing oxygen comprises applying a pressure of lower than 1×10E-4 Torr to said process chamber; and
heating said joining pre-assembly to a first joining temperature, thereby joining said first ceramic piece to said second ceramic.