A method for manufacturing a plurality of multi-pixel gas microsensors, wherein each multi-pixel gas microsensor comprises at least one or more pixels having a first sensing material and one or more pixels having a second sensing material different from the first material, the method comprising:
- A) providing a wafer substrate (10) comprising an insulation layer (12), and processing said wafer substrate for building the plurality of multi-pixel microsensors, said processing comprises at least steps of:
- A1) creating a lithography mask defining for each of the plurality of microsensors:
- i) one or more first electrode pairs (E1) forming a first pixel group (G1) corresponding to the first sensing material, and wherein each first electrode pair comprises a first and a second electrode,
- ii) one or more second electrode pairs (E2) forming a second pixel group (G2) corresponding to the second sensing material, and wherein each second electrode pair comprises a third and a fourth electrode, and
- iii) a first electrical connecting line connected with each of the first electrodes of the first electrode pairs (E1), and a second electrical connection line connected with each of the second electrodes of the first electrode pairs (E1),
- A2) applying a metallization process to said insulation layer for forming, for each of the plurality of microsensors, said first electrode pairs, said second electrode pairs, said first electrical connecting line and said second electrical connecting lines in accordance with the lithography mask, and wherein said metallization process comprises depositing one or more layers of metal on the substrate, and
- A3) depositing a protecting mask to the substrate, preferably made of nitride or oxide,
- B) selecting said first sensing material and said second sensing material, and wherein said first sensing material is a first polymer suitable for electropolymerization, and
- C) performing an on-wafer activation or an on-die activation of the first (G1) and second (G2) pixel group, said on-wafer or on-die activation comprising at least the steps of:
- C1) locally removing part of the protecting mask that is covering the first electrode pairs (E1) of the first pixel group (G1),
- C2) applying a first electropolymerization process for simultaneously coating each of the first electrode pairs (E1) of the first pixel group (G1) with said first sensing material, and wherein said first and second electrical connecting lines are used as electrical connections during said first electropolymerization process for applying a first voltage to said first and second electrode or for applying a first voltage difference between said first and second electrode,
- C3) locally removing part of the protecting mask that is covering the second electrode pairs (E2) of the second pixel group (G2), and
- C4) coating the second electrode pairs (E2) of the second pixel group with said second sensing material.