Low-resistive, CMOS-compatible ohmic contact schemes to moderately doped n-InP

Abstract

III-V laser integration on Si is seen as a promising path to overcoming the current interconnect bottleneck in computing. Therefore, III-V lasers need to be integrated with a CMOS-compatible process flow. Furthermore, parasitic elements of the lasers must be minimized while preventing trade-offs to the lasing action (i.e. doping level in the 1018 cm-3). One such parasitic element is the n-type ohmic contact on moderately doped n-InP. A detailed study of CMOS-compatible contacts on n-InP including structural analysis has not yet been performed. To fill this gap, we will comprehensively report on various metal contacts on n-InP that reach a record-low median specific contact resistivity of 6 × 10-8 ω • cm2 and on contacts that show very shallow alloying behavior while still offering a specific contact resistivity in the very low 10-7 ω • cm2 range.