Abstract: A gas injector includes a tubular rod segment that is made of a material selected from a group consisting of silicon and silicon carbide. The tubular rod segment includes a body defining a fluid passageway and threads machined directly on one end thereof. A knuckle includes threads. The threads of the tubular rod segment are connected to the threads of the knuckle. A gas supply tube is connected to the knuckle. One or more additional tubular rod segments can be attached by threads to the tubular rod segment to vary the length of the gas injector.

Abstract: A method of drilling holes comprises ductile mode drilling the holes in a component of a plasma processing apparatus with a cutting tool wherein the component is made of a nonmetallic hard and brittle material. The method comprises drilling each hole in the component by controlling a depth of cut while drilling such that a portion of the brittle material undergoes high pressure phase transformation and forms amorphous portions of the brittle material during chip formation. The amorphous portions of the brittle material are removed from each hole such that a wall of each hole formed in the component has an as drilled surface roughness (Ra) of about 0.2 to 0.8 ?m.

Abstract: A method of drilling holes comprises ductile mode drilling the holes in a component of a plasma processing apparatus with a cutting tool wherein the component is made of a nonmetallic hard and brittle material. The method comprises drilling each hole in the component by controlling a depth of cut while drilling such that a portion of the brittle material undergoes high pressure phase transformation and forms amorphous portions of the brittle material during chip formation. The amorphous portions of the brittle material are removed from each hole such that a wall of each hole formed in the component has an as drilled surface roughness (Ra) of about 0.2 to 0.8 ?m.