Heater block having continuous concavity

A heater block adapted to be installed in a plasma deposition or plasma etching apparatus comprising a showerhead and a reaction chamber, the heater block adapted to be arranged in the reaction chamber to support a substrate and comprising:

• at least one through-hole passing through the heater block, and
• on its upper face, a plurality of surfaces separated from each other and defined by a continuous concavity, the continuous concavity comprising:
• a plurality of first convexes at least partly defining a plurality of main concaves or depressions, and
• a concave channel connecting substantially every two adjacent main concaves or depressions,
• wherein a concave or depression at the center of the heater block is at least partly defined by inner sidewalls of a plurality of second convexes, and the contour of outer sidewalls of the plurality of second convexes has a circular or a polygonal shape, and
• wherein at least one first convex has a different shape from at least one second convex.

A processing apparatus comprising:

• a showerhead;
• a reaction chamber;
• and
• a heater block arranged in the reaction chamber, the heat block comprising:
• at least one through-hole passing through the heater block, and
• on its upper face, a plurality of surfaces separated from each other and defined by a continuous concavity, the continuous concavity comprising:
• a plurality of first convexes at least partly defining a plurality of main concaves or depressions,
• a concave channel connecting substantially every two adjacent main concaves or depressions, and
• a plurality of second convexes at least partly defining a concave or depression, at the center of the heater block, of a different shape or size from the plurality of main concaves or depressions,
• wherein at least one first convex has a different shape from at least one second convex.