UP - logo
E-viri
Celotno besedilo
Recenzirano Odprti dostop
  • Unravelling chemical etchan...
    Singh, Animesh Pratap; Xu, Han; Ghiami, Amir; Tang, Songyao; Wang, Zhaodong; Kalisch, Holger; Hoffmann-Eifert, Susanne; Daus, Alwin; Ingebrandt, Sven; Vescan, Andrei; Pachauri, Vivek

    Applied surface science, 10/2024, Letnik: 669
    Journal Article

    Display omitted •Systematic study of two-dimensional MoS2 layers during PMMA-assisted substrate transfers to assess the quality of wet-transfer process.•Chemical etchant such as KOH not only react to the growth substrate but also have unique influences on the 2D material.•2 to 5 M KOH concentrations allow rapid transfer with highest quality of MoS2 atomic layers.•A relationship between the use of optimal etchant concentrations and delamination time is established. Two-dimensional (2D) MoS2 is an emerging alternative to traditional semiconductors, overcoming scaling limits in device fabrication. Ongoing efforts to realize the full potential of 2D MoS2 in CMOS back-end-of-line integration encounters notable challenges due to synthesis of such 2D materials requiring high temperature growth substrates and a transfer step. Consequently, lattice preservation of MoS2 atomic layers during transfer from growth substrate to a target substrate is crucial for fabrication and system integration. This work, investigates the impact of commonly used chemical etchant potassium hydroxide (KOH) on MoS2 during the poly(methylmethacrylate) (PMMA) assisted wet-transfer process from sapphire substrates. A systematic experimental framework involving Raman spectroscopy, Atomic Force Microscopy (AFM), Optical Microscopy, and X-ray Photoelectron Spectroscopy (XPS) was employed for comparative evaluation of MoS2 upon transfer. While the investigations highlight the relation of etchant concentration and exposure time to be the deterministic factors, topographic and spectroscopic evidence corroborate the role of K+ ions in etching and oxidation of MoS2 at higher concentrations affecting the MoS2 quality. Thorough characterizations of transfer process, while following the MoS2 quality in this work, provides crucial information on etchant concentration selection to achieve shorter substrate transfer time with minimal impact on material quality.