using silk screened evaporated and sputtered al as the metal source, the formation of al back surface fields (bsf) was studied. the most satisfactory results were those obtained with the sputtered al and in which open circuit voltages (v/sub oc/) of 0.585v (12 omega cm fz silicon) have been achieved. the ultrasonic interconnect process is being verified. the process is generally satisfactory, but increased pull-strength may be obtained if some form of sintering is carried out on the metallized contacts. plasma etching has been shown to be feasible as a replacement for wet chemical cleaning prior to diffusion. an ipeg calculation shows its cost to be $0.005/watt peak (1975$). initial results on cells prepared by using electroless pd/ni plus either electroplated ag or cu have shown slightly poor performance than cells with the baseline evaporated ti/pd/ag system this is being further studied. a new mask has been designed for the 1.6 x 7.0 cm and 2.0 x 7.0 cm cells. this mask has a lower coverage and total lower resistive loss than the previous mask design. it is also shown that the cell width should not exceed 2.0 to 3.0 cm for optimum efficiency. (era citation 05:006718)