Chemical sensor with conductive cup-shaped sensor surface

Abstract

A system includes a sensor including a sensor pad and a well wall structure defining a well operatively coupled to the sensor pad. The well is further defined by a lower surface disposed over the sensor pad. The well wall structure defines an upper surface and defines a wall surface extending between the upper surface and the lower surface. The system further includes a conductive layer disposed over the lower surface and the wall surface.

What is claimed is: 
     
         1 . A system comprising:
 a sensor including a sensor pad;   a well wall structure defining a well operatively coupled to the sensor pad, the well further defined by a lower surface disposed over the sensor pad, the well wall structure defining an upper surface and defining a wall surface extending between the upper surface and the lower surface; and   a conductive layer disposed over the lower surface and extending incompletely up the wall surface.   
     
     
         2 . The system of  claim 1 , wherein the upper surface is free of the conductive layer. 
     
     
         3 . The system of  claim 1 , further comprising a passivation layer disposed over the conductive layer over the lower surface and the wall surface. 
     
     
         4 . The system of  claim 3 , wherein the passivation layer is further disposed over the upper surface of the well wall structure. 
     
     
         5 . The system of  claim 3 , wherein the passivation layer includes an oxide of aluminum, tantalum, hafnium, zirconium, or a combination thereof. 
     
     
         6 . The system of  claim 3 , further comprising a coating disposed over the passivation layer. 
     
     
         7 . The system of  claim 6 , wherein the coating includes a functional group selected from a group consisting of phosphate, phosphonate, catechol, nitrocatechol, boronate, phenylboronate, imidazole, silanol, another pH-sensing group, and a combination thereof. 
     
     
         8 . The system of  claim 1 , wherein the conductive layer is formed of a material having a volume resistivity of not greater than 6.0×10 7  ohm-m at 25° C. 
     
     
         9 . The system of  claim 8 , wherein the volume resistivity is not greater than 1.0×10 7  ohm-m at 25° C. 
     
     
         10 . The system of  claim 9 , wherein the volume resistivity is not greater than 5.0×10 6  ohm-m at 25° C. 
     
     
         11 . The system of  claim 10 , wherein the volume resistivity is not greater than 2.0×10 6  ohm-m at 25° C. 
     
     
         12 . The system of  claim 1 , wherein the conductive layer includes a metallic material. 
     
     
         13 . The system of  claim 12 , wherein the metallic material is copper, aluminum, titanium, gold, silver, platinum, or a combination thereof. 
     
     
         14 . The system of  claim 1 , wherein the conductive layer includes a ceramic material. 
     
     
         15 . The system of  claim 14 , wherein the ceramic material is titanium nitride, titanium aluminum nitride, titanium oxynitride, or a combination thereof. 
     
     
         16 . A method of forming a sensor system, the method comprising:
 forming a well wall structure defining a well operatively coupled to a sensor pad of a sensor, the well further defined by a lower surface disposed over the sensor pad, the well wall structure defining an upper surface and defining a wall surface extending between the upper surface and the lower surface;   forming a conductive layer over the lower surface and extending incompletely up the wall surface.   
     
     
         17 . The system of  claim 16 , wherein the conductive layer is formed of a material having a volume resistivity of not greater than 6.0×10 7  ohm-m at 25° C. 
     
     
         18 . The system of  claim 17 , wherein the volume resistivity is not greater than 1.0×10 7  ohm-m at 25° C. 
     
     
         19 . The system of  claim 18 , wherein the volume resistivity is not greater than 5.0×10 6  ohm-m at 25° C. 
     
     
         20 . The system of  claim 19 , wherein the volume resistivity is not greater than 2.0×10 6  ohm-m at 25° C. 
     
     
         21 . The system of  claim 16 , wherein the conductive layer includes a metallic material. 
     
     
         22 . The system of  claim 21 , wherein the metallic material is copper, aluminum, titanium, gold, silver, platinum, or a combination thereof. 
     
     
         23 . The system of  claim 16 , wherein the conductive layer includes a ceramic material. 
     
     
         24 . The system of  claim 23 , wherein the ceramic material is titanium nitride, titanium aluminum nitride, titanium oxynitride, or a combination thereof. 
     
     
         25 . The method of  claim 16 , further comprising forming a passivation layer over the planarized conductive layer. 
     
     
         26 . The system of  claim 25 , wherein the passivation layer includes an oxide of aluminum, tantalum, hafnium, zirconium, or a combination thereof. 
     
     
         27 . The system of  claim 16 , further comprising depositing a coating over the passivation layer. 
     
     
         28 . A method of sequencing a polynucleotide, the method comprising:
 depositing a polynucleotide conjugated polymeric particle in a well of a system, the system comprising:
 a sensor including a sensor pad; 
 a well wall structure defining a well operatively coupled to the sensor pad, 
 the well further defined by a lower surface disposed over the sensor pad, the well wall structure defining an upper surface and defining a wall surface extending between the upper surface and the lower surface; and 
 a conductive layer over the lower surface and extending incompletely up the wall surface; 
 applying a solution including a nucleotide to the well; and 
 detecting nucleotide incorporation in the well via the sensor pad of the sensor. 
   
     
     
         29 . The method of  claim 28 , wherein the polymeric particle includes multiple copies on the polynucleotide, and wherein a change in ionic concentration results from incorporation of the nucleotide with the polynucleotide, and wherein the change in ionic concentration changes an electrical characteristic of the sensor indicative of the nucleotide incorporation.