Engineering of AlON interlayer in Al2O3/AlON/In0.53Ga0.47As gate stacks by thermal atomic layer deposition

• Published in: Current applied physics 2018, 18(8), , pp.919-923
• Main Authors: Lee, Woo Chul, Cho, Cheol Jin, Park, Suk-In, Jun, Dong-Hwan, Song, Jin Dong, Hwang, Cheol Seong, Kim, Seong Keun
• Format: Article
• Language: English
• Subjects: AlON; Atomic layer deposition; InGaAs; Interface trap density; MOS capacitor; 물리학
• ISSN: 1567-1739; 1878-1675
• DOI: 10.1016/j.cap.2018.04.020

The presence of an AlN interfacial layer in high-k/In0.53Ga0.47As gate stacks improves the interfacial properties and enhances the electrical performance of devices. However, pure AlN is rarely grown by atomic layer deposition (ALD) because of the low reactivity of NH3 toward the common Al-precursor and the predisposition to oxidation of the grown AlN layer. Although a plasma-enhanced ALD technique significantly suppresses the oxygen content in the grown AlN layer, the deterioration of the interface properties by plasma-damage is a critical issue. In this work, an AlON interlayer was engineered by optimizing the NH3 feeding time in thermal ALD to improve the interface quality in Al2O3/AlON/In0.53Ga0.47As capacitors. It was determined that a mere increase in the NH3 feeding time during the ALD of the AlON film resulted in a higher nitrogen incorporation into the AlON interlayer, leading to a reduction in the interface trap density. Furthermore, the out-diffusion of elements from the In0.53Ga0.47As layer was effectively suppressed by increasing the NH3 feeding time. This work demonstrates that simple process optimization can improve the interface quality in high-k/In0.53Ga0.47As gate stacks without the use of any plasma-activated nitrogen source. [Display omitted] •The AlON interfacial passivation layer in the Al2O3/AlON/InGaAs stacks was engineered to improve the interfacial properties.•A longer feeding time of NH3 in the ALD of the AlON layer resulted in a reduction in the Dit of the Al2O3/AlON/InGaAs capacitors.•An increase in the NH3 feeding time contributed to effective suppression of out-diffusion of the substrate elements.