Hot wall rapid thermal processor
View Patent ↗An apparatus for heat treatment of a wafer. The apparatus includes a heating chamber having a heat source. A cooling chamber is positioned adjacent to the heating chamber and includes a cooling source. A wafer holder is configured to move between the cooling chamber and the heating chamber through a passageway and one or more shutters defines the size of the passageway. The one or more shutters are movable between an open position where the wafer holder can pass through the passageway and an obstructing position which defines a passageway which is smaller than the passageway defined when the shutter is in the open position.
1. A wafer holder for supporting a wafer in a heat treatment apparatus, comprising:
a support member having a surface to support the wafer;
an edge effect member located proximate and spaced apart from at least a portion of the peripheral edge of the wafer; wherein
the support member comprises a flat base plate extending the entire diameter of the wafer;
the edge effect member comprises a vertically oriented circular band perpendicular to the wafer and encircling at least a portion of the peripheral edge of the wafer; and
the thickness value t 1 of the flat plate and/or the thickness value t 2 of the edge effect member are in a range from about 0 to 10 mm to provide a thermal mass sufficient to slow the thermal ramp rate of periphery edge of the wafer.
2. The wafer holder of claim 1 wherein the thickness values t 1 and t 2 are in a range from about 0.75 to 2 mm.
3. A wafer holder for supporting a wafer in a heat treatment apparatus, comprising:
a support member for supporting the wafer;
an edge effect member located proximate and spaced apart from at least a portion of the peripheral edge of the wafer;
wherein the edge effect member has a thermal mass and is configured to slow the thermal ramp rate of the peripheral edge of the wafer and wherein the edge effect member has a thermal mass to energy absorption ratio greater than a thermal mass to energy absorption ratio of the wafer.
4. The wafer holder of claim 3 wherein the support member comprises a flat base plate extending the entire diameter of the wafer for supporting the wafer.
5. The wafer holder of claim 3 wherein the support member comprises a plurality of upwardly oriented pins for supporting the wafer.
6. The wafer holder of claim 3 wherein the support member comprises an annular ring for supporting the wafer.
7. The wafer holder of claim 3 wherein the edge effect member is spaced apart from the peripheral edge of the wafer at a distance of about 0.5 to 10 mm.
8. The wafer holder of claim 3 wherein the edge effect member is made of an opaque material selected from a group consisting of quartz, silicon carbide, alumina, fused silica, silicon, and ceramics.
9. The wafer holder of claim 3 wherein the edge effect member comprises a vertically oriented circular band perpendicular to the wafer and encircling at least a portion of the peripheral edge of the wafer, and the support member comprises an outwardly extending plate for supporting the wafer at the periphery of the wafer.
10. The wafer holder of claim 9 wherein the outwardly extending plate and the vertically oriented circular band are integral.
11. The wafer holder of claim 10 wherein the vertically oriented circular band encircles the entire peripheral edge of the wafer, and the outwardly extending plate supports the wafer along the periphery of the wafer.
12. The wafer holder of claim 3 wherein the edge effect member comprises a horizontally oriented circular band, the circular band is disposed underneath and parallel to the wafer and encircling at least a portion of the peripheral edge of the wafer, and the support member comprises a plurality of upwardly extended pins coupled to the band for engaging the underside of the wafer.
13. The wafer holder of claim 12 wherein the circular band encircles the entire peripheral edge of the wafer.
14. The wafer holder of claim 3 wherein the edge effect member comprises a horizontally oriented circular band, the circular band is disposed above and parallel to the wafer and encircling at least a portion of the peripheral edge of the wafer, and the support member comprises a plurality of L-shaped members coupled to the circular band and a plurality of upwardly projecting portions for engaging the underside of the wafer.
15. The wafer holder of claim 14 wherein the circular band encircles the entire peripheral edge of the wafer.
16. The wafer holder of claim 3 wherein:
the edge effect member comprises an upper portion and a lower portion,
the upper portion is comprised of a horizontally oriented circular band portion parallel to the wafer and disposed above the peripheral edge of the wafer;
the lower portion is comprised of a vertically oriented circular band portion perpendicular to the wafer;
the upper and lower portions encircle at least a portion of the peripheral edge of the wafer; and
the support member comprises an outwardly extending member coupled to the lower portion of the edge effect member and engaging the underside of the wafer.
17. The wafer holder of claim 16 wherein the upper and lower portions of the edge effect member encircle the entire peripheral edge of the wafer.