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A non-destructive method for detecting sub-micrometer-sized micropipes on an entire wafer surface is investigated. Since it is difficult to detect sub-micrometer-sized micropipes due to their small core size, a non-destructively and accurately detecting method is required. To solve the issue, we focus on a characteristic depression generated around micropipes, namely, line-shaped depressions. In this paper, the location of line-shaped depressions is identified by using optical inspection, and the line-shaped depressions are distinguished whether micropipes exhibit line-shaped depression or not by using mirror electron microscope observation as high-resolution inspection. The accuracy of the distinction results is confirmed by scanning electron microscope observation, and electrical characteristics of the P–N diode are fabricated using the inspected wafer. Furthermore, the sub-micrometer-sized micropipes are observed at the sites of leakage current identified by emission microscopy. Additionally, device simulation of the blocking-voltage characteristics of P–N diodes suggests that the increase in leakage current depends on the electric field at the sub-micrometer-sized micropipes, regardless of their core size. [ABSTRACT FROM AUTHOR]

We developed an in-operando x-ray topography method for dynamically visualizing single Shockley-type stacking fault (1SSF) expansion motions in silicon carbide (SiC) metal–oxide–semiconductor field-effect transistors (MOSFETs) during their operations and investigated the effect of the operating condition applied to the body diodes in SiC MOSFETs on dislocation glide velocity. In-operando x-ray topography observations were carried out in reflection geometry, and a high-resolution x-ray camera was used as a detector to record topographies dynamically. The sequence of 1SSF expansion motions in the SiC MOSFETs was observed at a high resolution of 1 s in x-ray topographies, which is sufficient to analyze the dislocation glide velocity of a 1SSF expansion. The observation results of changing the forward current density applied to the body diodes in SiC MOSFETs revealed that each triangular and bar-shaped 1SSF expands at different forward current densities. The 1SSF expansion timings also differed, even in the same chip under the same current density. The dislocation glide velocity of each expanded 1SSF in SiC MOSFETs was extracted, and it increased with the forward current density. Our method enables the dynamic visualization of bipolar degradation in SiC MOSFETs during their operations, and we can accurately obtain the information of when, where, and which 1SSF expands in a SiC MOSFET. [ABSTRACT FROM AUTHOR]

The effect of dopant profile engineering on planar MOSFETs fabricated using laser spike annealing (LSA) activation is examined. Results suggest 10 percent improvement in device performance as compared to conventional LSA devices.

A novel laser thermal process that dramatically enhances laser exposure windows by controlling the heating process in a self-limiting way is developed. Key technology is realized by introducing a new process combination of premorphization implantation and a heat absorber with a phase switch layer, and by optimizing them.

Boron segregation to regions close to the surface is examined.

We have quantitatively investigated how boron segregates to regions close to the surface, and what controls this phenomenon, using x-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and backside secondary ion mass spectrometry measurement techniques. We found that, contrary to the equilibrium segregation, the pileup of boron is mainly on and within 0.6 nm of the Si side of the interface, and that there is no difference between the kind of encapsulation. This also suggests that the pileup of boron is mainly on the Si side, and implies that the main factor in this segregation is the existence of the Si surface. From the viewpoint of device fabrication, this result seems to be useful in terms of the fabrication of sidewalls. The possibility of boron pileup to occurring in the interstitial state was also shown. Our results suggested a way of looking at dopant profiles by predictive computer modeling. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]