A method of forming a thermoelectric device includes extruding a P/N-type billet to form a P/N-type extrusion having a first plurality of P-type regions and a first plurality of N-type regions. The P/N-type extrusion is sliced into a plurality of P/N-type wafers. A diffusion barrier metallization is applied to at least a subset of the P-type regions and N-type regions. One side of at least one P/N-type wafer is attached to a temporary substrate. The P/N-type regions of the P/N-type wafer are separated into an array of isolated P-type and N-type elements. The array of elements are coupled to a first plate having a first patterned metallization to form a thermoelectric circuit. The temporary substrate and bonding media may be detached from the P-type and N-type elements. The thermoelectric circuit may be coupled with a second plate at a second end of the thermoelectric circuit, second plate having a second patterned metallization.