Control of phosphorus doping profiles for co-diffusion processes
We present an innovative versatile POCl3 diffusion process. Two separate deposition stages allow for independent manipulation of depth and surface concentration in one diffusion step. This manipulation is achieved solely by variation of the N2-POCl3 gas flow during deposition. The thermal budget of the diffusion process is suitable for simultaneous diffusion from borosilicateglass (BSG). This makes this process a promising candidate for co-diffusion for a wide range of advanced solar cell concepts. The wide applicability is supported by measurements of the contact resistance and dark saturation current density that prove tunability with respect to both parameters.