US 2024/0200191 A1 · BACKSIDE DEPOSITION PREVENTION ON SUBSTRATES

Abstract

Various systems and methods are provided to prevent backside deposition on a substrate by using a combination of approaches. The approaches include clamping the substrate to a pedestal and/or supplying purge gases to an area where deposition is not desired. The clamping methods include electrostatic or vacuum clamping. In addition, various pedestal and edge ring designs are provided for supplying purge gases to the area where deposition is not desired. The use of clamping in conjunction with purging can further enhance the performance without affecting deposition of materials on front side of the substrate. The clamping along the edge of the substrate can be made more effective by machining an upper surface of the pedestal to have a slight dish or dome like shape (i.e., concave or convex, respectively).

Claims75

Dependent claims

A pedestal comprising:

a base portion to support a substrate, the base portion being disc shaped and having an annular recess on an upper surface of the base portion along an outer diameter of the base portion;
a stem portion connected to the base portion;
a heat shield arranged below a lower surface of the base portion, the heat shield and the lower surface defining a manifold that is in fluid communication with a gas inlet;
and
an edge ring including:
a cylindrical portion surrounding the base portion and having a first end resting on an outer edge of the heat shield and a second end, an inner surface of the cylindrical portion and an outer surface of the base portion defining a first gap in fluid communication with the manifold;
and
an annular portion extending radially inwards over the annular recess from the second end of the cylindrical portion, the annular portion and the annular recess defining a second gap in fluid communication with the first gap;
wherein a purge gas supplied to the gas inlet flows through the manifold, the first and second gaps, and radially outwards over the annular portion.

6 more elements

A pedestal to support a substrate, the pedestal comprising:

a base portion having a disc shape and including:
an annular ridge on an upper surface, the annular ridge having an outer diameter less than an outer diameter of the base portion and having an inner diameter greater than or equal to an outer diameter of the substrate;
an annular protrusion on a lower surface, the annular protrusion having a diameter less than the inner diameter of the annular ridge and the outer diameter of the substrate;
and
a plurality of holes extending outwardly from the lower surface to the upper surface, the holes arranged along a first circle on the upper surface and along a second circle on the lower surface, the first circle having a first diameter that is less than the inner diameter of the annular ridge and the outer diameter of the substrate and greater than the diameter of the annular protrusion, and the second circle having a second diameter that is less than the diameter of the annular protrusion;
and
a stem portion extending from the base portion.

4 more elements

Dependencies are inferred from the claim text.

Backside deposition prevention on substrates

Life of this patent

Backside deposition prevention on substrates

Life of this patent

Abstract

Claims75