US 6,144,040 A · Van der pauw structure to measure the resistivity of a doped area under diffusion areas and gate structures

Abstract

The present invention provides a van der Pauw semiconductor test structure for and a method of testing a resistivity of a doped area formed within a substrate of a semiconductor wafer which may be under a diffusion area or a gate structure. The test structure can include field oxide regions formed on a surface of the substrate and a base doped substrate formed within the substrate. Further, the test structure includes a first primary tub and secondary tubs that are formed within the base doped substrate, each of the secondary tubs having a first diffusion region formed adjacent to an inner isolation structure and a second diffusion region formed adjacent to an outer isolation structure. A second primary tub is located adjacent the first primary tub and a dielectric layer is formed over the substrate having contacts formed within the dielectric layer and between the isolation structures. Further still, the test structure may include a gate structure as part of the semiconductor test structure, with the gate structure having openings formed therein through which the contacts extend to the first diffusion regions and the second diffusion regions.

Claims16

Dependent claims

A van der Pauw semiconductor test structure for testing a resistivity of a doped area formed within a semiconductor wafer, comprising:

a first primary tub doped with a first-type dopant and formed within a substrate of the semiconductor wafer that is doped with a second-type dopant having a polarity opposite that of the first-type dopant;
at least four secondary tubs each doped with the first-type dopant and partially overlapping the primary tub to connect each of the secondary tubs to the first primary tub, each of the secondary tubs including an inner isolation structure and a first diffusion region doped with the first-type dopant and a second diffusion region doped with the second-type dopant, the inner isolation structure electrically isolating the first diffusion region from the second diffusion region, each of the first diffusion regions having a first contact connected thereto and each of the second diffusion regions having a second contact connected thereto;
a second primary tub doped with the second-type dopant and located adjacent the first primary tub;
and
an outer isolation structure covering a substantial portion of the substrate and partially extending inside the primary tub and each of the secondary tubs, the outer isolation structure isolating the second diffusion region from the second primary tub.

2 more elements

A method for testing a resistivity of a doped area formed in a substrate of a semiconductor wafer using a van der Pauw semiconductor test structure comprising a first primary tub doped with a first-type dopant, a second primary tub doped with a second-type dopant and located adjacent the first primary tub, first, second, third and fourth secondary tubs each doped with the first-type dopant and including an inner isolation structure and a first diffusion region doped with the first-type dopant and a second diffusion region doped with a second-type dopant, each of the first-type diffusion regions having a first contact connected thereto and each of the second-type diffusion regions having a second contact connected thereto, the method comprising;

applying a first voltage to electrical contacts connected to the second primary tub;
applying a second voltage to one or more of the second contacts of the first, second, third and fourth secondary tubs;
then
determining a first resistance of the doped area by:
applying a first current between the first contacts of the first and second secondary tubs;
and
measuring a third voltage between the first contacts of the third and fourth secondary tubs;
and then
determining a second resistance of the doped area by
applying a second current between the first contacts of the first and third secondary tubs;
and
measuring a fourth voltage between the first contacts of the second and fourth secondary tubs;
and then
determining a sheet resistance of the doped area from the first and second resistances.

11 more elements

Dependencies are inferred from the claim text.

Van der pauw structure to measure the resistivity of a doped area under diffusion areas and gate structures

Life of this patent

Van der pauw structure to measure the resistivity of a doped area under diffusion areas and gate structures

Life of this patent

Abstract

Claims16