Scanning spreading resistance microscopy study of a metalorganic chemical vapor deposited grown InP optoelectronic structure

Abstract

Scanning spreading resistance microscopy (SSRM) is a promising new tool for dopant profiling in semiconductor materials. We present the results of a SSRM study of the cross section of a metalorganic chemical vapor deposited grown optoelectronic structure. The SSRM measurements are compared with the secondary ion mass spectrometry (SIMS) and excellent spatial agreement is obtained. However, we find that obtaining quantitative agreement with SIMS is complicated by the differing nonlinear I-V characteristics of n- and p-type InP. The results suggest that obtaining quantitative agreement with SIMS would require calibration of each SSRM probe tip with both n- and p-type materials. The high spatial resolution of the technique is demonstrated by our ability to easily resolve the 17.5 nm quantum well and barrier layer structure of the device. The results suggest that the greatest strength of SSRM will be the delineation of complex buried semiconductor structures.

Degradation kinetics of ultrathin HfO2 layers on Si(100) during vacuum annealing monitored with in situ XPS/LEIS and ex situ AFM

“…2). We speculate that the initially microscopic areas of HfO 2 degradation further promote degradation around themselves, giving rise to circular areas with Hf silicide in the center and at the perimeter, the latter fact confirmed with the spreading resistance microscopy allowing to measure local conductivity with high lateral resolution [17] (Fig. 2b).…”

Electrical Scanning Probe Microscopy: Investigating the Inner Workings of Electronic and Optoelectronic Devices

“…Also shown is the current obtained at a reverse bias of −0.5 V. Strong contrast in SSRM current among quantum wells and barrier layers is obtained only at forward DC bias (0.5 V), indicating a strongly nonlinear dependence of the SSRM current on the sample bias. 17 An upward slope in the SSRM current in the active region can be observed in both curves; this behavior may be a consequence of the potential drop in the MQW active region (up to around 1 V) due to the built-in electrical field across the p-i-n junction. Figure 7 shows the averaged spreading resistance as a function of depth below the device surface in the p-n-p-n structure region.…”

“…SSRM and SCM require the use of conductive probes with good material hardness and electrical conductivity. Previously reported results on III-V compound semiconductor samples 17 revealed that the probes that yield the best quantitative correlation between SSRM and SCM measurements and secondary ion mass spectrometry (SIMS) results are commercially available boron-doped ( p-type) diamond-coated cantilever tips (Digital Instruments, spring constant = 40 N/m). Figure 3 shows a scanning electron microscope (SEM) image of a probe of this type.…”

“…A simple cleave was made to expose the cross-section of the p-n junction. 17 Current-voltage characteristics of the samples were measured before, during, and after the SVM experiment-stable electrical device characteristics were obtained at all times. AFM images of the sample surface obtained simultaneously with the SSRM and SVM data showed no perceptible topographic features.…”

“…106,107 The SSRM technique resolves free carrier distribution within a semiconductor device but only at equilibrium. 17,18,23 The present authors describe a technique they call scanning differential spreading resistance microscopy (SDSRM). SDSRM is used to investigate the free carrier distribution inside a BH MQW laser under both zero bias and forward biases.…”