Probe methodology for ultrafine pitch interconnects
Representative implementations of devices and techniques provide a temporary access point (e.g., for testing, programming, etc.) for a targeted interconnect located among multiple finely spaced interconnects on a surface of a microelectronic component. One or more sacrificial layers are disposed on the surface of the microelectronic component, overlaying the multiple interconnects. An insulating layer is disposed between a conductive layer and the surface, and includes a conductive via through the insulating layer that electrically couples the conductive layer to the target interconnect. The sacrificial layers are configured to be removed after the target interconnect has been accessed, without damaging the surface of the microelectronic component.
1. A method, comprising:
depositing a removable insulating layer on a die surface, over a plurality of conductive interconnects on the die surface;
forming an opening in the insulating layer above a target interconnect on the die surface, the opening exposing the target interconnect;
depositing a removable conductive fill within the opening, the conductive fill forming a conductive via through the insulating layer electrically coupled to the target interconnect;
depositing a removable conductive layer over the conductive via and a portion of the insulating layer, the conductive layer electrically coupled to the conductive via and overlaying a portion of the plurality of conductive interconnects on the die surface; and
externally accessing the target interconnect from the conductive layer, while insulating the target interconnect from other interconnects of the plurality of conductive interconnects and insulating the other interconnects of the plurality of conductive interconnects from the conductive layer with the insulating layer; and
removing the insulating layer, the conductive fill, and the conductive layer after the target interconnect has been externally accessed.
2. The method of claim 1 , further comprising externally accessing the target interconnect from the conductive layer with a probe device having a probe tip that is larger than a spacing between the target interconnect and at least one of the other interconnects of the plurality of conductive interconnects, without shorting the target interconnect to any of the other interconnects of the plurality of conductive interconnects.
3. The method of claim 1 , further comprising:
forming one or more additional openings in the insulating layer above one or more peripheral interconnects on the die surface, the one or more additional openings exposing the one or more peripheral interconnects;
depositing the removable conductive fill within the one or more additional openings, the conductive fill forming one or more additional conductive vias through the insulating layer electrically coupled to the one or more peripheral interconnects; and
temporarily electrically coupling the target interconnect and the one or more peripheral interconnects through the conductive layer.
4. The method of claim 1 , further comprising depositing one or more additional removable layers between the conductive layer and the die surface, the conductive via electrically coupling the conductive layer to the target interconnect through the one or more additional layers.
5. The method of claim 4 , further comprising removing the one or more additional removable layers after the target interconnect has been externally accessed.
6. The method of claim 1 , further comprising sending or receiving a signal through the target interconnect prior to removing the insulating layer, the conductive fill, and the conductive layer.
7. The method of claim 1 , further comprising enabling or programming the die through the target interconnect prior to removing the insulating layer, the conductive fill, and the conductive layer.
8. The method of claim 1 , further comprising using a highly-selectable chemical and/or mechanical etching to remove each of the insulating layer, the conductive fill, and the conductive layer without damaging an underlying layer of each, respectively.
9. The method of claim 8 , further comprising planarizing the die surface and bonding the die surface to a surface of another microelectronic component using a direct bonding technique without adhesive.
10. The method of claim 1 , further comprising providing security to the die by restricting access to the target interconnect by removing the insulating layer, the conductive fill, and the conductive layer after the target interconnect has been externally accessed.