Probe apparatus, a process of forming a probe head, and a process of forming an electronic device
A probing apparatus includes a set of conductors configured to contact a surface of a workpiece simultaneously. A processor activates subsets of the conductors to determine a four-point-probe parameter, wherein the subset is less than the set of conductors. Another subset determines another four-point-probe parameter. The set of conductors remain in contact with the surface of the workpiece during and between activating each subset. A process of forming a probe head includes a probe substrate and associated conductive leads. An insulating layer is formed over the probe substrate and patterned to expose the leads. Conductors, connected to the leads, are formed over the insulating layer and define a probing area of a least 250 cm 2 .A process of forming an electronic device includes contacting a surface of a workpiece using conductors. Subset of the conductors are activated to determine four-point-probe parameters at different areas of the workpiece.
1. A process of forming a probe head comprising:
providing a probe substrate including conductive leads and having a primary surface;
forming an insulating layer over the probe substrate;
patterning the insulating layer to expose the conductive leads;
forming, over the insulating layer, conductors that are to contact a surface of a workpiece being tested, wherein the conductors define a probing area of at least 250 cm 2 ; and
forming straps to provide a conductive path between the conductive leads and the conductors.
2. The process of claim 1 , wherein the insulating layer is to deflect from a shape when a force is applied to the conductors and to return substantially to the shape after the force is removed.
3. The process of claim 1 , further comprising:
forming a sacrificial member before forming the insulating layer;
patterning the insulating layer to expose a portion of the sacrificial member; and
removing the sacrificial member to define a void, wherein the void is disposed between the probe substrate and a particular conductor of the conductors, along a line substantially perpendicular to the primary surface of the probe substrate.
4. The process of claim 1 , wherein:
forming the conductors over the insulating layer wherein the conductors define a probing area of at least 1100 cm 2 .
5. The process of claim 1 , further comprising:
providing an interface to the probe head wherein:
a first subset of the conductors is to facilitate probing a first portion of the workpiece;
a second subset of the conductors is to facilitate probing a second portion of the workpiece; and
a surface of the workpiece and the conductors remain in contact during and between probing using the first subset of conductors and probing using the second subset of conductors.
6. The process of claim 5 , wherein:
the first subset of the conductors is configured as a four-point probe; and
the second subset of the conductors is configured as a different four-point probe.
7. A process of forming an electronic device comprising:
contacting a surface of a workpiece using conductors;
activating a first subset of the conductors to determine a first four-point-probe parameter corresponding to a first local area of the workpiece;
activating a second subset of the conductors to determine a second four-point-probe parameter corresponding to a second local area of the workpiece, wherein:
the first subset is different from the second subset; and
the surface of the workpiece and the conductors remain in contact between activating the first subset of the conductors and activating the second subset of the conductors.
8. The process of claim 7 , further comprising forming a conductive layer over substantially all of a substrate before contacting the surface of the workpiece, wherein the workpiece includes the conductive layer and the substrate.
9. The process of claim 8 , further comprising determining a thickness of the conductive layer, wherein the determination is performed using the first four-point-probe parameter, the second four-point-probe parameter, or a combination thereof.
10. The process of claim 9 , further comprising thickening the conductive layer after contacting the surface the workpiece, activating the first subset of the conductors, and activating the second subset of the conductors.
11. The process of claim 7 , further comprising:
forming an insulating layer over a substrate;
forming a conductive layer over the insulating layer and the substrate;
removing a first portion of the conductive layer to form the surface of the workpiece; and
determining whether a sufficient amount of the conductive layer has been removed.
12. The process of claim 11 , wherein determining whether the sufficient amount of the conductive layer has been removed comprises determining whether a part of the insulating layer is exposed by using the first four-point-probe parameter, the second four-point-probe parameter, or a combination thereof.
13. The process of claim 11 , further comprising:
removing a second portion of the conductive layer;
activating a third subset of the conductors to determine a third four-point-probe parameter; and
determining whether the sufficient amount of the conductive layer has been removed.
14. The process of claim 13 , wherein:
the first and second subsets of the conductors are characterized by a first pitch; and
the third and fourth subsets of the conductors are characterized by a second pitch different from the first pitch.
15. The process of claim 7 , wherein contacting the surface of the workpiece using conductors further comprises:
advancing the conductors towards the workpiece until initial contact with the workpiece occurs; and
overdriving the conductors by an additional amount after initial contact between the conductors and the workpiece has occurred.
16. The process of claim 7 , wherein the conductors define a probing area of at least 250 cm 2 .
17. The process of claim 16 , further comprising:
forming a sacrificial member before forming the insulating layer;
patterning the insulating layer to expose a portion of the sacrificial member; and
removing the sacrificial member to define a void, wherein the void is disposed between the probe substrate and a particular conductor of the conductors, along a line substantially perpendicular to the primary surface of the probe substrate.
18. The process of claim 16 , further comprising:
providing an interface to the probe head wherein:
a first subset of the conductors is to facilitate probing a first portion of the workpiece;
a second subset of the conductors is to facilitate probing a second portion of the workpiece; and
a surface of the workpiece and the conductors remain in contact during and between probing using the first subset of conductors and probing using the second subset of conductors.
19. The process of claim 18 , wherein:
the first subset of the conductors is configured as a four-point probe; and
the second subset of the conductors is configured as a different four-point probe.