Characterization of n-n Ge/SiC heterojunction diodes

Gammon, P. M.; Pérez‐Tomás, Amador; Jennings, Michael R.; Roberts, G. J.; Davis, M. C.; Shah, V. A.; Burrows, S. E.; Wilson, Neil R.; Covington, James A.; Mawby, P.A.

doi:10.1063/1.2987421

Cited by 9 publications

(7 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With a surface roughness of only 6.7 nm the polycrystalline layer could easily be polished to a flat from here. Figure 1c shows an n-type 300 nm layer that has been grown at only 200 o C, compared to the rest that have been grown at 500 o C. A trade off exists in selecting deposition temperature, as we first reported for 100 nm layers 12 . The raised deposition temperatures give polycrystalline layers, with low resistance but poor surface morphology, forming good contacts.…”

Section: A Physical Analysismentioning

confidence: 82%

“…The surface roughness values (R q ) over this area for all the 300 nm heterojunction layers are summarised in Table I. The thinnest heterojunction layer is shown in Figure 1b, where the layer was grown at high temperature to a thickness of only 100 nm. We previously carried out a full analysis on this layer 12 , citing the Stranski Krastanov growth mode as the reason why the large islands form, with gaps almost down to the SiC between them. By comparing this image with Figure 1a, we can see that there is substantial improvement in the layer quality as it gets thicker.…”

Section: A Physical Analysismentioning

confidence: 99%

“…More recently, we have reported on Ge/SiC heterojunctions 12,13 due to the materials even higher mobility (especially in p-type where the hole mobility is 5 times that of Si and 21 times that of SiC) and the development of very good Ge/High-K dielectric interfaces 14 . With the Ge having been deposited via MBE and given ohmic front and back contacts, Schottky-like behaviour was demonstrated with the structures displaying a turn-on voltage of only 0.3 V and an ideality factor less than 1.1.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Interface characteristics of n-n and p-n Ge/SiC heterojunction diodes formed by molecular beam epitaxy deposition

Gammon

Pérez‐Tomás

Jennings

et al. 2010

Journal of Applied Physics

Self Cite

View full text Add to dashboard Cite

In this article, we report on the physical and electrical nature of Ge/SiC heterojunction layers that have been formed by MBE deposition. Using X-ray diffraction, atomic force microscopy and helium ion microscopy, we perform a thorough analysis of how MBE growth conditions affect the Ge layers. We observe the layers developing from independent islands at thicknesses of 100 nm to flat surfaces at 300 nm. The crystallinity and surface quality of the layer is shown to be affected by the deposition parameters and, using a high temperature deposition and a light dopant species, the layers produced have large polycrystals and hence a low resistance. The p-type and n-type layers, 300 nm thick are formed into Ge/SiC heterojunction mesa diodes and these are characterised electrically. The polycrystalline diodes display near ideal diode characteristics (n < 1.05), low on resistance and good reverse characteristics. Current-voltage measurements at varying temperature prove that all the layers have two-dimensional fluctuations in the Schottky barrier height (SBH) due to inhomogeneities at the heterojunction interface. Capacitance-voltage analysis and the SBH size extracted from I-V analysis suggest strongly that interface states are present at the surface causing Fermi-level pinning throughout the bands. A simple model is used to quantify the concentration of interface states at the surface.

show abstract

Section: A Physical Analysismentioning

confidence: 82%

Section: A Physical Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Interface characteristics of n-n and p-n Ge/SiC heterojunction diodes formed by molecular beam epitaxy deposition

Gammon

Pérez‐Tomás

Jennings

et al. 2010

Journal of Applied Physics

Self Cite

View full text Add to dashboard Cite

show abstract

“…On the other hand, silicon carbide (SiC) is another wide bandgap semiconductor material (up to 3.26 eV) with high thermal conductivity, high breakdown voltage and fast switching speed, making it an attractive candidate for high power and high frequency devices [13,14]. SiC is also known for its excellent mechanical properties and good chemical stability [15,16]. Most of these properties are related to the crystalline structure and the many varieties of polytypes presented by SiC, where the most studied ones are the 3C-SiC, 4H-SiC and 6H-SiC polytypes [14].…”

Section: Introductionmentioning

confidence: 99%

Zinc oxide thin films on silicon carbide substrates (ZnO/SiC): electro-optical properties and electrically active defects

Felix

Aziz

Araujo

et al. 2014

Semicond. Sci. Technol.

View full text Add to dashboard Cite

The electrical and optical properties of heterojunctions formed by thermally deposited ZnO thin films on n-type 4H-SiC substrates have been investigated. Current-voltage characteristics of the fabricated light emitting devices revealed excellent rectifying behaviors with a typical leakage current lower than 1 nA at a reverse bias of −3 V, and with a forward current at 3 V in the range of 2 mA. A study of the electroluminescent characteristics of ZnO/SiC heterojunctions over the temperature range of 50-450 K showed an emission peak around 410 nm and a broad defect-related electroluminescence at room temperature in the visible range for a forward current of 300 mA. Electrically active deep level centers in ZnO and n-type 4H-SiC epilayers have been investigated by deep level transient spectroscopy (DLTS) and high-resolution Laplace DLTS (LDLTS). Additionally, LDLTS has successfully been employed to resolve the closely spaced hole trap energy levels.

show abstract

“…17,18 On the other hand, silicon carbide (SiC) is a wellknown material for its extraordinary mechanical and physical properties such as hardness, abrasive wear resistance, chemically inert, and high thermal conductivity. 19,20 There are many polytypes, but the technologically important ones are 3C-, 4H-, and 6H-SiC. In general, 3C-SiC is known as a low-temperature polytype, while 4H-and 6H-SiC as hightemperature polytypes.…”

mentioning

confidence: 99%

Investigation of deep-level defects in conductive polymer on n-type 4H- and 6H-silicon carbide substrates using I-V and deep level transient spectroscopy techniques

Felix

Aziz

Cunha

et al. 2012

Journal of Applied Physics

View full text Add to dashboard Cite

The current-voltage (I–V) characteristics of Au/sulfonated polyaniline (SPAN)/n-SiC heterojunctions have been investigated in detail over a wide range of temperatures between 20 and 440 K. The measured I–V characteristics of all devices show a good rectification behavior at all temperatures. The room temperature rectification ratios (forward to reverse currents ratio, IF/IR) at 0.6 V for SPAN/n-type 4H-SiC and SPAN/n-type 6H-SiC heterojunctions are 2 × 104 and 7 × 106, respectively. The value of rectification of SPAN/6H-SiC heterojunction is four orders of magnitutude higher than the state-of-the art sulfonated polyaniline thin films deposited on n-type silicon substrates. A self-assembly technique and copolymerization were used to fabricate a self-doped polyaniline films on SiC substrates. The experimental I–V data were analysed using the Werner model, which includes the series resistance of the heterojunctions. The diode parameters such as the ideality factor and the barrier height are determined from the experimental data using I–V analysis method. The effect of the temperature on these parameters is presented. Deep level transient spectroscopy (DLTS) and Laplace DLTS techniques were used to investigate the electrically active defects present in these heterostructure devices.

show abstract

Characterization of n-n Ge/SiC heterojunction diodes

Cited by 9 publications

References 7 publications

Interface characteristics of n-n and p-n Ge/SiC heterojunction diodes formed by molecular beam epitaxy deposition

Interface characteristics of n-n and p-n Ge/SiC heterojunction diodes formed by molecular beam epitaxy deposition

Zinc oxide thin films on silicon carbide substrates (ZnO/SiC): electro-optical properties and electrically active defects

Investigation of deep-level defects in conductive polymer on n-type 4H- and 6H-silicon carbide substrates using I-V and deep level transient spectroscopy techniques

Contact Info

Product

Resources

About