The use of carbon nanotubes (CNT) as interconnects in future integrated circuits (IC) is being considered as a replacement for copper. As this research needs also innovative metrology solutions, we have developed a combined approach for the plane-view analysis of CNT integrated in contact holes where transmission electron microscopy (TEM) enables the quantitative measurement of density and structure of the CNT and where scanning spreading resistance microscopy (SSRM) is used to electrically map the distribution of the CNT. This paper explains the used methodologies in detail and presents results from 300 nm diameter contact holes filled with CNT of 8-12 nm in diameter and a density of about 2 x 1011 cm-2.

The successful implementation of silicon nanowire (NW)-based tunnel-field effect transistors (TFET) critically depends on gaining a clear insight into the quantitative carrier distribution inside such devices. Therefore, we have developed a method based on scanning spreading resistance microscopy (SSRM) which allows quantitative two-dimensional (2D) carrier profiling of fully integrated NW-based TFETs with 2 nm spatial resolution. The keys in our process are optimized NW cleaving and polishing steps, in-house fabricated diamond tips with ultra-high resolution, measurements in high-vacuum and a dedicated calibration procedure accounting for dopant dependant carrier mobilities.

The characterization of doped regions inside silicon nanowire structures poses a challenge which must be overcome if these structures are to be incorporated into future electronic devices. Precise cross-sectioning of the nanowire along its longitudinal axis is required, followed by two-dimensional electrical measurements with nanometer spatial resolution. The authors have developed an approach to cross-section silicon nanowires and to characterize them by scanning spreading resistance microscopy (SSRM). This paper describes a cleaving- and polishing-based cross-sectioning method for silicon nanowires. High resolution SSRM measurements are demonstrated for epitaxially grown and etched silicon nanowires.

Junction formation in FinFET-based 3D-devices is a challenging problem as one targets a complete conformal doping of the source/drain regions in order to produce equal gate-profile overlaps (and thus transistor behavior) on all sides of the fins. Due to the lack of predictive modeling for several of the doping strategies explored (plasma immersion, cluster implants, vapor phase deposition, etc…) it becomes difficult to correctly predict the performance of the devices and hence, accurate 3D-doping profile determination is desired. Although several dopant/carrier profiling methods exist with excellent one- or two-dimensional resolution and properties, there is an urgent need to extend these towards a quantitative three-dimensional geometry. In this work, we use scanning spreading resistance microscopy (SSRM) with dedicated FinFET test structure to obtain three-dimensional information from successive two-dimensional scanning spreading resistance maps. We also assess the validity of our methodology by comparing various sections along the fins which represent the variability due to the processing and measurement procedure.

The advantages of fluorine co-implantation on reducing the deep P junction profile is investigated and commented as a possible valuable solution for further scaling of the NMOS transistors spacer length. On PMOS transistors, Ge+C+B cocktail junctions lead to improved short channel effects control, S/D resistance and performance over the conventional approaches. Additional laser annealing induces a partial dissolution of the doping clusters in the junction and lower the S/D transistors resistance. A performance improvement is demonstrated both for NMOS and PMOS with cocktail junctions activated by spike RTA and additional laser annealing.

Within this paper we have demonstrated the unique capability of scanning spreading resistance microscopy (SSRM) in order to evaluate and optimize the recent approaches towards the formation of advanced p-MOS devices. As shown in this paper, such an optimization requires a detailed 2D-analysis on completely processed devices as two-dimensional interactions may cause (unexpected) lateral diffusion and (de) activation of underlying profiles. Emphasis will be on junction formation using Ge- pre-amorphization and carbon based cocktail implantation coupled with activation based on solid phase epitaxial regrowth and/or millisecond laser anneal. In the case of a Ge-pre-amorphization implant followed by solid phase epitaxial regrowth, SSRM shows an obvious relationship between the presence of defects in the end of range region and halo implant de-activation. Based on the quantified 2D-profiles we can extract the lateral and vertical junction depths as well as the lateral and vertical abruptness of the extension region. A drastic reduction of the lateral diffusion for the cocktail implant versus the standard reference devices with classical spike annealing is eminent. At the same an important reduction of the lateral diffusion of the source/drain implants (HDD) under the spacer can be seen. The SSRM results also highlight the impact of different activation mechanisms on the channel implants (in particular on the shape of the halo pockets).

We present B junction extensions that are extremely abrupt and shallow manufactured by amorphization, C co-implantation and conventional rapid thermal annealing (RTA). Resulting junctions have abruptnesses of 2 nm/dec better than as-implanted profiles. The most shallow B junction that has been manufactured is 15 nm deep and Rs = 626 Ω/sq. Successful implementation of these junctions is straightforward for P-MOS 30 nm gate length devices.