Photoreflectance characterization of ultrashallow junction activation in millisecond annealing

Abstract

Photoreflectance ͑PR͒ provides an optical means for rapid and precise measurement of near-surface electric fields in semiconductor materials. This article details the use of PR to characterize dopant activation in ultrashallow junction ͑USJ͒ structures formed using millisecond annealing processes. USJ structures were formed in silicon using 500 eV B implantation with a dose of 10 15 / cm 2 , followed by flash anneals at 1250-1350°C. Reference metrology was performed using secondary ion mass spectrometry and various sheet resistance ͑R s ͒ methods. Methods to calibrate PR signals to active carrier concentration in USJ structures, including halo-doped samples, are described. PR is shown to be highly sensitive to active dopant concentrations in USJ structures formed by millisecond annealing.

Z-scanning laser photoreflectance as a tool for characterization of electronic transport properties

“…. It should be noted the dependence of ∆R on Z is indentical to the dependence shown in Eq (12). since in this case the 1/ω 2 (Z) term of Eq.…”

“…PR spectroscopy has been used to determine semiconductor bandstructures, internal electric fields, carrier concentration, and other material properties such as crystallinity, alloy composition, and physical strain [11]. Laser photoreflectance (LPR) techniques comprising the use of a laser probe beam in the conventional PR apparatus are generally well-suited for use in semiconductor device manufacturing as they are non-contact and can be performed rapidly with micrometer scale resolution [12].…”

Precise Optical Measurement of Carrier Mobilities Using Z-scanning Laser Photoreflectance

“…through the dependence of Eq. ( 1) on N e ) [19]. Therefore, provided the active dopant concentration can be determined from the LPR amplitude at focus, the mobility as measured from the Z -scanning LPR technique may be used to characterize the sheet resistance R s via the relation R s ∝ 1/µN e .…”

Impact of diffusionless anneal using dynamic surface anneal on the electrical properties of a high-k/metal gate stack in metal-oxide-semiconductor devices

“…12 As transistors are scaled aggressively, the formation of ultrashallow junctions ͑USJs͒ with lower sheet resistance is required to overcome the short channel effects. 13 Therefore, alternative millisecond annealing techniques such as the flash anneal 14,15 or dynamic surface anneal ͑DSA͒ ͑Ref. 16͒ to conventional RTA have been suggested due to the higher dopant activation and lower dopant diffusion.…”