Atomic layer deposition and other thin film deposition techniques: from principles to film properties

Thin film is a modern technology aimed at improving the structural, electrical, magnetic, optical, and mechanical properties of bulk materials. This technology has so far found applications in integrated circuits, semiconductor devices, transistors, light-emitting diodes, light crystal displays and photoconductors, rectifiers, solar cells, sensors, and micro-electromechanical systems (MEMS). Methods of thin film deposition such as physical and chemical vapor deposition (PVD and CVD), sputtering, spin and dip coatings, and spray pyrolysis have been utilized for several years. But in recent times, the atomic layer deposition (ALD) technique has attracted the attention of researchers. In this current review, we have explored the most used techniques in the depositions of thin film materials with a focus on the properties of film produced, and the advantages and disadvantages of each technique. Generally, it was observed that the quality of films produced by these techniques depends greatly on the choice of substrate, deposition temperature, temperature window, and precursor used. It concluded by identifying ALD as an optimum technique in depositing ultra-thin film materials due to its simplicity, reproducibility, control over film composition and thickness, and high conformal deposited films at the atomic level. This study has established the opportunity for upcoming researchers to have an insight of selecting the most suitable technique for their study in various fields of research. Finally, the challenges and future perspectives of deposition techniques were highlighted.