Wafer holder for supporting a semiconductor wafer during a thermal treatment process
View Patent ↗A wafer holder for holding a semiconductor wafer during a thermal wafer treatment process. The wafer holder includes at least three wafer supports. Each wafer support includes an upright shaft and a plurality of flexible fibers supported by the shaft in positions such that at least some of the fibers engage the semiconductor wafer when the wafer rests on the wafer supports.
1. A wafer holder for holding a semiconductor wafer during a thermal wafer treatment process, said wafer holder comprising at least three wafer supports, each wafer support comprising an upright shaft and a plurality of flexible fibers supported by the shaft in positions such that at least some of the fibers engage said semiconductor wafer when the wafer rests on the wafer supports, wherein at least some of the fibers of at least one wafer support are arranged to form a wool body.
2. A wafer holder as set forth in claim 1 wherein the wool body has first and second opposite ends, the first end is secured to the shaft, and the second end is spaced from the shaft by a distance in a range from about 1 mm to about 5 mm.
3. A wafer holder as set forth in claim 2 wherein the wool body has a total volume in a range from about 15 mm 3 to about 100 mm 3 .
4. A wafer holder as set forth in claim 1 wherein the fibers have an average diameter in a range from about 15 microns to about 50 microns.
5. A wafer holder for holding a semiconductor wafer during a thermal wafer treatment process, said wafer holder comprising at least three wafer supports, each wafer support comprising an upright shaft and a plurality of flexible fibers supported by the shaft in positions such that at least some of the fibers engage said semiconductor wafer when the wafer rests on the wafer supports, wherein the shaft has a circumferential sidewall defining a cavity extending axially into the shaft at one end of the shaft and the fibers are at least partially received in said cavity, and wherein said sidewall has a plurality of openings extending through the sidewall to reduce thermal conductivity of the sidewall.
6. A wafer support for holding a semiconductor wafer during a thermal treatment process, said wafer support comprising an elongate shaft having an end and a plurality of flexible fibers supported by the end of the shaft in positions such that the fibers are engageable with a surface of said semiconductor wafer oriented so said surface is generally horizontal, the fibers being made of a material that retains at least some weight-bearing capacity when exposed to a temperature of at least about 900 degrees centigrade, wherein at least some of the fibers are arranged to form a wool body.
7. A method of treating a semiconductor wafer, the method comprising:
supporting the semiconductor wafer with a support so its weight is distributed over a plurality of flexible fibers;
heating the wafer to a temperature of at least about 900 degrees centigrade while the wafer is supported by the fibers; and
maintaining a structural integrity of the support while conducting a minimum amount of heat to and/or from the wafer.
8. A method of treating a semiconductor wafer, the method comprising:
setting the semiconductor wafer on a wafer holder, the wafer holder comprising at last three wafer supports configured for use in the thermal wafer treatment process, each of said supports comprising a plurality of flexible fibers, the setting step comprising: (a) resting the wafer on a first fiber of said plurality of fibers; (b) permitting the first fiber to bend under the weight of the wafer; (c) resting the wafer on another fiber of said plurality; (d) permitting said other fiber to bend under the weight of the wafer; and (e) repeating steps (c) and (d) until the weight of the wafer causes no further bending of the fibers; and
heating the wafer while it is supported by the fibers.
9. A wafer holder for holding a semiconductor wafer during a thermal wafer treatment process, said wafer holder comprising at least three wafer supports configured for use in the thermal wafer treatment process, each wafer support comprising an upright shaft and a plurality of flexible fibers supported by the shaft in positions such that at least some of the fibers engage said semiconductor wafer when the wafer rests on the wafer supports;
wherein each wafer support has a tapered cavity for receiving the plurality of flexible fibers.
10. A wafer holder as set forth in claim 9 wherein each cavity tapers from a larger diameter at an upper end of the shaft to a smaller diameter away from the upper end of the shaft.