Depth‐resolved compositional analysis of W/B4C multilayers using resonant soft X‐ray reflectivity. (5th April 2019)

• Record Type: Journal Article
• Authors: Rao, P. N.; Goutam, U. K.; Kumar, Prabhat; Gupta, Mukul; Ganguli, Tapas; Rai, S. K.
• Is Part Of: Journal of synchrotron radiation. Volume 26:Part 3(2019)
• Page Start: 793
• Page End: 800
• Publication Date: 2019-04-05
• Subjects: X‐ray multilayers -- extreme ultraviolet lithography -- optical index -- composition -- boron carbide -- resonant reflectivity; Synchrotron radiation -- Periodicals; Free electron lasers -- Periodicals; 539.73505
• DOI: 10.1107/S1600577519002339
• Languages: English
• ISSNs: 0909-0495

Abstract

Abstract : W/B4 C multilayer structures are characterized using various experimental techniques. The influence of B4 C layer thickness on the optical performance near the B K ‐edge is discussed. Abstract : W/B4 C multilayers (MLs) consisting of ten layer pairs with varying boron carbide layer thicknesses have been investigated. The ML structures were characterized using grazing‐incidence hard X‐ray reflectivity (GIXR), resonant soft X‐ray reflectivity (RSXR), hard X‐ray photoelectron spectroscopy (HAXPES) and X‐ray absorption near‐edge spectroscopy (XANES). Depth‐resolved spectroscopic information on the boron carbide layer in W/B4 C MLs was extracted with sub‐nanometre resolution using reflectivity performed in the vicinity of the B K ‐edge. Interestingly, these results show that the composition of boron carbide films is strongly dependent on layer thicknesses. HAXPES measurements suggest that most of the boron is in the chemical state of B4 C in the multilayer structures. XANES measurements suggest an increase in boron content and C—B—C bonding with increase in boron carbide layer thickness.