Ductile mode drilling methods for brittle components of plasma processing apparatuses

A method of ductile mode drilling 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 comprising:

• 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;
• and
• removing amorphous portions of the brittle material 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 μm;
• wherein the ductile mode drilling is performed with a drill speed of about 20,000 to 60,000 revolutions per minute, a feed rate at about 0.5 to 1.5 inches per minute, a peck depth of about 0.001 to 0.004 inch, and a depth of cut less than about 450 nanometers per revolution.