Scanning spreading resistance microscopy and spectroscopy for routine and quantitative two-dimensional carrier profiling

Abstract

As emphasized in the International Technological Roadmap for Semiconductors (ITRS), two-dimensional carrier profiling is one of the key elements in support of technology development. Scanning spreading resistance microscopy (SSRM) has been demonstrated to have attractive concentration sensitivity, an easy quantification, and is applicable to complementary metal–oxide–semiconductor Si and InP structures. Its commercial implementation and availability together with an ample supply of appropriate (diamond based) tips has enabled its more widespread use during recent years. In this article we propose a number of measurement procedures and software tools for its more reliable and fast routine application. First we present a program for the automatic generation of calibration curves and the fast quantification of one-dimensional and two-dimensional resistivity (and carrier) profiles. In view of the large tip consumption, a fast evaluation and calibration of newly mounted conductive tips is a major issue. Furthermore, the fast extraction of the underlying carrier distributions leads to an easier data interpretation. We also propose an overview of the implementation and of the applications of the scanning spreading resistance spectroscopy (SSRS), where a full I–V curve is collected at each measurement point. SSRS proves to be particularly interesting to study the point-contact characteristics (in scanning mode) and simplifies significantly the junction delineation. SSRS can also be used for the selection of the optimal bias settings for the quantification procedure.

Characterization of an ultrashallow junction structure using angle resolved x-ray photoelectron spectroscopy and medium energy ion scattering

“…On the other hand, scanning spreading resistance microscopy ͑SSRM͒ is a newly developed two-dimensional carrier profiling which has good concentration sensitivity and easy quantification in the semiconductor industry. 2 The junction delineation accuracy and reproducibility of the SSRM technique on ultrashallow implants are evaluated in ultrathin nand p-type extension implants by Eyben et al 3 However, use of this technique is beyond the work of this article and is not studied here.…”

Force modulation for improved conductive-mode atomic force microscopy

“…Major challenges are related to sustaining a highquality electrical contact while not losing spatial resolution over a prolonged tip lifetime. The fast degradation of the tip apex due to wear and admission of high areal current densities lead to a high probe consumption in routine characterization measurements [2] and prohibit the use of electrical probes in probe-based data storage on phase-change media [3].…”

Practical issues in carrier‐contrast imaging of GaN structures

“…Here, a metal-coated tip is biased, and the resistance between the tip and a broad area contact (which is dominated by the spreading resistance) is measured. However, SSRM only gives carrier concentration, not type [2].…”