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An optical emission microscopy technique with spatial and spectral resolution capabilities is applied for stability studies of 4H–SiC material properties. From the example of a 4H–SiC p[sup +]/n[sup -]/n[sup +] diode imaged at different stages of electrical overstress the mechanism of degrading performance is directly unveiled. We correlate this phenomenon with irreversible structural changes within the active region created by a nonuniform heating related stress. The stress-generated features are interpreted as multiple stacking faults spreading throughout the whole base region and nucleated in the vicinity of built-in defects and process-induced structural deficiencies. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Studies the ambipolar Auger coefficient from measurements of temperature dependence in electron irradiated and highly n-type silicon. Extraction of effective ambipolar lifetime; Consideration of varying injection levels and temperatures; Room temperature value of Auger coefficient.

Investigates the injection and temperature dependence of the Shockley-Read-Hall (SRH) carrier lifetime. Significance of the carrier lifetime for electronic devices; Techniques used to obtain the SRH lifetime under low-level injection; Description of the capture coefficients for electrons and holes for the recombination center.

Presents a detailed experimental analysis of the ambipolar diffusion coefficient in silicon regarding both temperature and injection-level dependence. Measurement of the ambipolar diffusion coefficient; Use of the open-circuit-carrier decay method based on the free-carrier absorption technique.

Presents information on the observation of near-surface electrically active defects in n-type 6H-SiC. What is the most commonly used technique for the identification and characterization of electrically active defects in semiconductors; Details on the experiment; Results from the experiment.

Investigates the irreversible formation of a network of linear defects in silicon carbide injection diodes. Relation of the defects to dislocations; Result of the thermal stress near the tip of the contact probe; Effect of higher forward currents.

Heavily Al-doped 4H–SiC structures have been prepared by vapor phase epitaxy. Subsequent anneals have been carried out in an Ar atmosphere in a rf-heated furnace between 1500 °C and 2000 °C for 0.5 to 3 h. Secondary ion mass spectrometry has been utilized to obtain Al concentration versus depth as well as lateral distributions (ion images). Transmission electron microscopy (TEM) has been employed to study the crystallinity and determine phase composition after heat treatment. A solubility limit of ∼2×10[sup 20] Al/cm[sup 3] (1900 °C) is extracted. Three-dimensional ion images show that the Al distribution does not remain homogeneous in layers heat treated at 1700 °C or above when the Al concentration exceeds 2×10[sup 20] cm[sup -3]. Al-containing precipitates are identified by energy-filtered TEM. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Experimental evidence is given for transient enhanced diffusion of boron (B) in ion-implanted silicon carbide (SiC). The implanted B is diffusing several μm into the samples when annealed at 1600 and 1700 °C for 10 min, but the in-diffused tails remain unaffected when the annealing times are increased to 30 min at the same temperatures. A lower limit of the effective B diffusivity at 1600 °C is determined to 7x10[sup -12] cm[sup 2]/s, which is 160 times larger than the equilibrium B diffusivity given in the literature. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]