The structural, optical, and electrical properties of Al-doped ZnO (ZnO:Al) thin films deposited by atomic layer deposition (ALD) with a modified precursor pulse sequence were investigated to evaluate the electromagnetic interference shielding effectiveness (EMI-SE). A Zn-Al-O precursor exposure sequence was used in a modified ALD procedure to result in better distribution of Al 3+ ions in the ZnO matrix with the aim of reducing the formation of complete nano-laminated structures that may form in the typical alternating ZnO and Al 2 O 3 deposition procedure. The ALD dopant concentration of the ZnO:Al films was varied by adjusting the dopant deposition intervals of the ZnO:ZnAlO precursor pulse cycle ratios among 24:1, 19:1, 14:1, and 9:1. The lowest obtained resistivity and average transmittance in the visible region (380-780 nm) were 5.876 × 10 -4 Ω cm (carrier concentration of 6.02 × 10 20 cm -3 and Hall mobility of 17.65 cm 2 /V s) and 85.93% in the 131 nm thick ZnO:Al(19:1) film, respectively. The average value of the EMI-SE in the range of 30 MHz to 1.5 GHz increased from 1.1 dB for the 121 nm thick undoped ZnO film to 6.5 dB for the 131 nm thick ZnO:Al(19:1) film.
Bibliographical noteFunding Information:
This work was supported by the Industrial Strategic Technology Development Program ( 10041926 , development of high density plasma technologies for thin film deposition of nanoscale semiconductor and flexible display processing) funded by the Ministry of Knowledge Economy (MKE, Korea).
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Surfaces, Coatings and Films