STRESS RELIEF IN SEMICONDUCTOR WAFERS
Methods for compensating for warpage in a semiconductor structure comprising an epitaxial layer grown on a semiconductor substrate. The methods include forming a buffer layer on the epitaxial layer and forming a compensating layer on the buffer layer; forming a buffer layer on the semiconductor substrate and forming a compensating layer on the buffer layer; and forming grooves in the epitaxial layer.
1 ) A semiconductor wafer comprising:
a substrate of a semiconductor material having first and second major surfaces;
an epitaxial layer formed on the first surface of the substrate;
a buffer layer formed on the epitaxial layer; and
a compensating layer formed on the buffer layer and compensating for warpage in the epitaxial layer.
2 ) The semiconductor wafer of claim 1 wherein grooves are formed in the epitaxial layer to reduce its warpage.
3 ) The semiconductor wafer of claim 2 wherein the grooves are substantially parallel and aligned with the contours of the warpage.
4 ) The semiconductor wafer of claim 1 wherein one of the epitaxial layer and the compensating layer has compressive stress and the other has tensile stress.
5 ) A semiconductor wafer comprising:
a substrate of a semiconductor material having first and second major surfaces;
an epitaxial layer formed on the first surface of the substrate;
a buffer layer formed on the second surface of the substrate; and
a compensating layer formed on the buffer layer and compensating for warpage in the epitaxial layer.
6 ) The semiconductor wafer of claim 5 wherein grooves are formed in the epitaxial layer to reduce its warpage.
7 ) The semiconductor wafer of claim 6 wherein the grooves are substantially parallel and aligned with the contours of the warpage.
8 ) The semiconductor wafer of claim 5 wherein both the epitaxial layer and the compensating layer have compressive stress or both layers have tensile stress.
9 ) A semiconductor wafer comprising:
a substrate of a semiconductor material having first and second major surfaces;
an epitaxiaxial layer formed on the first surface of the substrate; and
grooves in the epitaxial layer.
10 ) A method for compensating for warpage in a semiconductor wafer comprising:
forming an epitaxial layer on a first major surface of a semiconductor wafer;
forming a buffer layer on the epitaxial layer;
forming a compensating layer on the buffer layer, the compensating layer compensating for warpage in the epitaxial layer.
11 ) The method of claim 10 further comprising forming grooves in the epitaxial layer.
12 ) The method of claim 10 wherein one of the epitaxial layer and the compensating layer has compressive stress and the other has tensile stress
13 ) A method for compensating for warpage in a semiconductor wafer comprising:
forming an epitaxial layer on a first major surface of a semiconductor wafer;
forming a buffer layer on a second major surface of the semiconductor wafer;
forming a compensating layer on the buffer layer, the compensating layer compensating for warpage in the epitaxial layer.
14 ) The method of claim 13 further comprising forming grooves in the epitaxial layer.
15 ) The method of claim 13 wherein both the epitaxial layer and the compensating layer have compressive stress or both layers have tensile stress.
16 ) A method for compensating for warpage in a semiconductor wafer comprising:
forming an epitaxial layer on a first major surface of a semiconductor wafer;
forming a buffer layer on the epitaxial layer;
forming grooves in the epitaxial layer.
17 ) The method of claim 16 wherein the grooves are substantially parallel.