Atomic Layer Deposition of p‐Type Semiconducting Thin Films: a Review

Abstract Semiconductors such as elemental silicon allowing both p‐type and n‐type doping are the backbone of the current microelectronics industry, while the continuous progress in fabrication techniques has been the key for ever‐increasing integration density and device miniaturization. Similarly, in the strongly emerging field of transparent electronics both p‐type and n‐type compound semiconductors are needed that moreover should be transparent within the entire visible spectral range. Atomic layer deposition (ALD) has been the thin‐film deposition method of choice for a number of challenging applications in microelectronics, and it would also be a highly relevant technology for transparent electronics. Currently the appropriate p‐type semiconducting compounds are far outnumbered by the n‐type compounds. Hence there is an obvious search for high‐quality thin films of new p‐type compound semiconductors. This is clearly seen in the increasing number of ALD papers published annualy on p‐type semiconducting materials. In this overview the current state of research in the field is briefly presented; the ALD processes so far developed for the various p‐type (transparent) conducting material candidates are summarized, and the most prominent electrical transport and optical properties achieved for these thin films are highlighted.