Sacrificial wafer probe pads through seal ring for electrical connection to circuit inside an integrated circuit
The disclosure is directed to a semiconductor wafer, integrated circuit product, and method of making same, having multiple non-singulated chips separated by scribe lines, comprising a plurality of seal rings, each seal ring surrounding a corresponding chip and disposed between the corresponding chip and adjacent scribe lines. Well resistors are disposed below the seal rings and probe pads disposed in the scribe lines. In particular, at least one of the probe pads is coupled by at least one of the well resistors to at least one of the chips.
1. A semiconductor wafer having multiple non-singulated chips separated by scribe lines, comprising:
a plurality of seal rings disposed on a surface of a semiconductor substrate, each seal ring surrounding a corresponding chip and disposed between the corresponding chip and adjacent scribe lines;
probe pads disposed in the scribe lines; and
a plurality of doped regions disposed in the semiconductor substrate, each of the plurality of doped regions configured to form a corresponding well resistor,
wherein at least one of the well resistors extends from at least one of the chips to at least one of the probe pads and having a portion that passes directly under a corresponding seal ring of the plurality of seal rings, so as to couple the at least one of the probe pads to the at least one of the chips.
2. The semiconductor wafer of claim 1 , wherein the probe pads comprise sacrificial probe pads that are destroyed when the wafer is diced.
3. The semiconductor wafer of claim 1 , wherein each seal ring comprises a bottom metallization layer electrically isolated from the corresponding chip.
4. The semiconductor wafer of claim 1 , further comprising a connecting stack to couple the at least one probe pad to the at least one of the well resistors, wherein the at least one probe pad and the connecting stack are disposed in the same scribe line.
5. The semiconductor wafer of claim 1 , further comprising a connecting stack to couple the at least one probe pad to the at least one of the well resistors, wherein the at least one probe pad is disposed in a first scribe line and at least a portion of the connecting stack is disposed in an adjacent intersecting scribe line.
6. The semiconductor wafer of claim 1 , further comprising a conductive interconnect via between a bottom metal layer of the at least one probe pad and the at least one of the well resistors.
7. The semiconductor wafer of claim 6 , wherein the conductive interconnect via includes silicide or is formed using silicide.
8. The semiconductor wafer of claim 1 , further comprising a non-conductive interconnect via between a bottom layer of at least one of the seal rings and the at least one of the well resistors.
9. The semiconductor wafer of claim 8 , wherein the non-conductive interconnect via does not include silicide, and therefore is non-conductive.
10. The semiconductor wafer of claim 1 , wherein the at least one probe pad is coupled by the at least one of the well resistors to an active device of the corresponding chip.
11. The semiconductor wafer of claim 1 , wherein the well resistors are disposed in the semiconductor substrate.
12. The semiconductor wafer of claim 1 , wherein a first seal ring defines an inner portion of the corresponding chip encapsulated by the first seal ring and defines an outer portion of the corresponding chip that is not encapsulated by the first seal ring, and
wherein the at least one of the well resistors extends from the inner portion to the outer portion.
13. The semiconductor wafer of claim 1 , wherein the at least one of the well resistors is directly connected to the corresponding seal ring, and
wherein the at least one of the well resistors is electrically isolated from the corresponding seal ring.
14. The semiconductor wafer of claim 1 , further comprising a circuit element disposed on the corresponding chip, the circuit element directly contacting the at least one of the well resistors,
wherein the at least one probe pad directly contacts the at least of the well resistors so as to be electrically connected to the circuit element via the at least one of the well resistors.
15. An integrated circuit product having multiple non-singulated chips separated by scribe lines, comprising:
a plurality of seal rings disposed on a surface of a semiconductor substrate, each seal ring surrounding a corresponding chip and disposed between the corresponding chip and adjacent scribe lines; and
a plurality of doped regions disposed in the semiconductor substrate, each of the plurality of doped regions configured to form a corresponding well resistor,
wherein two or more chips are electrically coupled by at least one well resistor so as to provide a conductive interconnect between the two or more chips, and
wherein the at least one well resistor extends from a first chip of the two or more chips to a second chip of the two or more chips and having a portion that passes directly under a corresponding seal ring of the plurality of seal rings.
16. The integrated circuit product of claim 15 , wherein each seal ring comprises a bottom metallization layer electrically isolated from the corresponding chip.
17. The integrated circuit product of claim 15 , wherein the doped regions are electrically isolated from metal layers of the seal rings.
18. A method of making a semiconductor wafer having a plurality of chips separated by scribe lines, comprising:
forming a plurality of doped regions in a semiconductor substrate, each of the plurality of doped regions configured to form a corresponding well resistor;
forming a seal ring on a surface of the semiconductor substrate around a corresponding chip so as to be disposed between the corresponding chip and adjacent scribe lines; and
forming probe pads in the scribe lines,
wherein at least one of the well resistors extends from the corresponding chip to the at least one probe pad and having a portion that passes directly under the seal ring.
19. The method of claim 18 , further comprising singulating the chips at least at a subset of the scribe lines.
20. The method of claim 18 , wherein forming the probe pads comprises forming a conductive interconnect via between a bottom metal layer of the at least one probe pad and the at least one of the well resistors.
21. The method of claim 20 , wherein the conductive interconnect via includes silicide or is formed using silicide.
22. The method of claim 18 , wherein forming the seal ring further comprises forming a bottom metallization layer electrically isolated from the corresponding chip.
23. The method of claim 22 , wherein forming the seal ring comprises forming a non-conductive interconnect via between a bottom metal layer of the seal ring and the at least one of the well resistors.
24. The method of claim 18 , further comprising coupling the at least one probe pad by a second one of the well resistors to a second chip.
25. The method of claim 18 , further comprising forming connecting stacks to couple the probe pads to the well resistors.
26. An integrated circuit product, comprising:
a silicon substrate having a doped region configured to form a well resistor;
an integrated circuit chip disposed on the silicon substrate and encapsulated by a seal ring formed on a surface of the silicon substrate; and
a probe pad located in a scribe area adjacent to the seal ring,
wherein the well resistor extends from the probe pad to an internal circuit of the integrated circuit chip, the well resistor having a portion that passes directly under the seal ring.
27. The integrated circuit product of claim 26 , wherein the well resistor is mechanically connected to a bottom metal layer of the seal ring, but electrically isolated from the bottom metal layer of the seal ring.
28. The integrated circuit product of claim 26 , further comprising:
a conductive interconnect between a bottom metal layer of the probe pad and the well resistor; and
a non-conductive interconnect between a bottom metal layer of the seal ring and the well resistor.
29. A semiconductor wafer having a first chip and a second chip separated by a scribe line, the wafer comprising:
a semiconductor substrate having a doped region that defines a well resistor;
a seal ring disposed on a surface of the semiconductor substrate about a circumference of the first chip, and separating the first chip from the scribe line;
a probe pad disposed in the scribe line, the probe pad directly contacting the well resistor; and
a first circuit element disposed on the first chip, the first circuit element directly contacting the well resistor,
wherein the well resistor extends from the probe pad to the first chip, the well resistor having a portion that passes directly under the seal ring.
30. The semiconductor wafer of claim 29 , wherein the well resistor is directly connected to the seal ring, and
wherein the well resistor is electrically isolated from the seal ring.
31. The semiconductor wafer of claim 30 , wherein the well resistor is connected to the seal ring via a non-conducting metallization layer of the seal ring.