18 research outputs found
Considerably long carrier lifetimes in high-quality 3C-SiC(111)
As a challenge and consequence due to its metastable nature, cubic silicon carbide (3C-SiC) has only shown inferior material quality compared with the established hexagonal polytypes. We report on growth of 3C-SiC(111) having a state of the art semiconductor quality in the SiC polytype family. The x-ray diffraction and low temperature photoluminescence measurements show that the cubic structure can indeed reach a very high crystal quality. As an ultimate device property, this material demonstrates a measured carrier lifetime of 8.2 mu s which is comparable with the best carrier lifetime in 4 H-SiC layers. In a 760-mu m thick layer, we show that the interface recombination can be neglected since almost all excess carriers recombines before reaching the interface while the surface recombination significantly reduces the carrier lifetime. In fact, a comparison of experimental lifetimes with numerical simulations indicates that the real bulk lifetime in such high quality 3C-SiC is in the range of 10-15 mu s
Lateral Enlargement Growth Mechanism of 3C-SiC on Off-Oriented 4H-SiC Substrates
We introduce a 3C-SiC growth concept on off-oriented 4H-SiC substrates using a sublimation epitaxial method. A growth model of 3C-SiC layer development via a controlled cubic polytype nucleation on in situ formed on-axis area followed by a lateral enlargement of 3C-SiC domains along the step-flow direction is outlined. Growth process stability and reproducibility of high crystalline quality material are demonstrated in a series of 3C-SiC samples with a thickness of about 1 mm. The average values of full width at half-maximum of Ļ rocking curves on these samples vary from 34 to 48 arcsec indicating high crystalline quality compared to values found in the literature. The low temperature photoluminescence measurements also confirm a high crystalline quality of 3C-SiC and indicate that the residual nitrogen concentration is about 1ā2 Ć 1016 cmā3. Such a 3C-SiC growth concept may be applied to produce substrates for homoepitaxial 3C-SiC growth or seeds which could be explored in bulk growth of 3C-SiC
Sublimation growth of thick freestanding 3C-SiC using CVD-templates on silicon as seeds
Cubic silicon carbide is a promising material for medium power electronics operating at high frequencies and for the subsequent growth of gallium nitride for more efficient light emitting diodes. We present a new approach to produce freestanding cubic silicon carbide (3C-SiC) with the ability to obtain good crystalline quality regarding increased domain size and reduced defect density. This would pave the way to achieve substrates of 3C-SiC so that the applications of cubic silicon carbide material having selectively (111) or (001) oriented surfaces can be explored. Our method is based on the combination of the chemical vapor deposition method and the fast sublimation growth process. Thin layers of cubic silicon carbide grown heteroepitaxially on silicon substrates are for the first time used for a subsequent sublimation growth step to increase layer thicknesses. We have been able to realize growth of freestanding (001) oriented 3C-SiC substrates using growth rates around 120 Ī¼m/h and diameters of more than 10 mm. The structural quality from XRD rocking curve measurements of (001) oriented layers shows good FWHM values down to 78 arcsec measured over an area of 1 Ć 2 mm2, which is a quality improvement of 2ā3 times compared with other methods like CVD.Funding agencies|Angpanneforeningen Research Foundation||Swedish Energy Agency||Bundesministerium fur Bildung und Forschung (BMBF)| 03SF0393 |</p
http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-73672 Sublimation growth of thick freestanding 3C-SiC using CVD-templates on silicon as seeds
using CVD-templates on silicon as seed
Original Publication:
http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-73704 Geometrical control of 3C and 6H-SiC nucleation on low off-axis substrate
Design and inculcation of modern technologies of tax planning, protection of assets and information in enterprisesin Latvia and worldwide for tax optimization purposes
MaÄ£istra darba nosaukums ir ā Modernu nodokļu plÄnoÅ”anas, aktÄ«vu un informÄcijas aizsardzÄ«bas tehnoloÄ£iju izstrÄde un ievieÅ”ana praksÄ Latvijas un pasaules uzÅÄmumos ar mÄrÄ·i optimizÄt nodokļu maksÄjumusā.
Galvenais darba mÄrÄ·is ir izpÄtÄ«t Ärzonu (offshore) jurisdikcijÄs bÅ«tÄ«bu, aprakstÄ«t vajadzÄ«gus risinÄjumus, pierÄdÄ«t modernu nodokļu plÄnoÅ”anas ievieÅ”anas izdevÄ«gumu, kÄ arÄ« izanalizÄt ar to saistÄ«tas problÄmas. Otrais mÄrÄ·is ir apskatÄ«t nodokļu plÄnoÅ”anas attÄ«stÄ«bas tendences LatvijÄ un pasaulÄ, kÄ arÄ« moderna nodokļu plÄnoÅ”anas pakalpojumu virzienu attÄ«stÄ«bu.
Darbs sastÄv no ievada, 4 iztirzÄjuma nodaļÄm, secinÄjumiem un priekÅ”likumiem. Darba pirmajÄ daļa tika veikta vispÄrÄ«ga zemu nodokļu jurisdikciju analÄ«ze, kÄ arÄ« aplÅ«kotas Å”o jurisdikciju attÄ«stÄ«bas tendences. Darba otrajÄ daÄ¼Ä tika pÄtÄ«ts biznesa sektors, korporatÄ«vÄs funkcijas un zemu nodokļu jurisdikciju darbÄ«bas shÄmas. TreÅ”ajÄ daÄ¼Ä tika veikta informÄcijas un aktÄ«vu aizsardzÄ«bas tehnoloÄ£iju un shÄmu analÄ«ze. CeturtajÄ daÄ¼Ä tika izstrÄdÄta jauna straptautiskÄs holdinga kompÄnijas struktÅ«ra, kÄ arÄ« tika identificÄtas starptautisko holdinga kompÄniju izmantoÅ”anas priekÅ”rocÄ«bas ar mÄrÄ·i optimizÄt nodokļu maksÄjumus.
PÄc autora domÄm Ŕī pÄtÄ«juma galvenais secinÄjums ir ā nodokļu plÄnoÅ”anas tirgus LatvijÄ atrodas attÄ«stÄ«bas stÄvoklÄ« un lÄ«dz ar to ir grÅ«ti prognozÄjams. TajÄ notiekoÅ”ie darÄ«jumi ieÅem ievÄrojamu vietu valsts kopÄjÄ finansu tirgÅ«. Nodokļu plÄnoÅ”anas tirgus attÄ«stÄ«bas pamatÄ ir ekonomiskÄ stabilitÄte valstÄ«, sakÄrtota likumdoÅ”ana, nodroÅ”inÄÅ”anÄs pret nelabvÄlÄ«gu faktoru ietekmi, kÄ arÄ« paÅ”mÄju un Ärzemju kapitÄla piesaiste.
MaÄ£istra darba nosaukums ir ā Modernu nodokļu plÄnoÅ”anas, aktÄ«vu un informÄcijas aizsardzÄ«bas tehnoloÄ£iju izstrÄde un ievieÅ”ana praksÄ Latvijas un pasaules uzÅÄmumos ar mÄrÄ·i optimizÄt nodokļu maksÄjumusā.
Galvenais darba mÄrÄ·is ir izpÄtÄ«t Ärzonu (offshore) jurisdikcijÄs bÅ«tÄ«bu, aprakstÄ«t vajadzÄ«gus risinÄjumus, pierÄdÄ«t modernu nodokļu plÄnoÅ”anas ievieÅ”anas izdevÄ«gumu, kÄ arÄ« izanalizÄt ar to saistÄ«tas problÄmas. Otrais mÄrÄ·is ir apskatÄ«t nodokļu plÄnoÅ”anas attÄ«stÄ«bas tendences LatvijÄ un pasaulÄ, kÄ arÄ« moderna nodokļu plÄnoÅ”anas pakalpojumu virzienu attÄ«stÄ«bu.
Darbs sastÄv no ievada, 4 iztirzÄjuma nodaļÄm, secinÄjumiem un priekÅ”likumiem. Darba pirmajÄ daļa tika veikta vispÄrÄ«ga zemu nodokļu jurisdikciju analÄ«ze, kÄ arÄ« aplÅ«kotas Å”o jurisdikciju attÄ«stÄ«bas tendences. Darba otrajÄ daÄ¼Ä tika pÄtÄ«ts biznesa sektors, korporatÄ«vÄs funkcijas un zemu nodokļu jurisdikciju darbÄ«bas shÄmas. TreÅ”ajÄ daÄ¼Ä tika veikta informÄcijas un aktÄ«vu aizsardzÄ«bas tehnoloÄ£iju un shÄmu analÄ«ze. CeturtajÄ daÄ¼Ä tika izstrÄdÄta jauna straptautiskÄs holdinga kompÄnijas struktÅ«ra, kÄ arÄ« tika identificÄtas starptautisko holdinga kompÄniju izmantoÅ”anas priekÅ”rocÄ«bas ar mÄrÄ·i optimizÄt nodokļu maksÄjumus.
PÄc autora domÄm Ŕī pÄtÄ«juma galvenais secinÄjums ir ā nodokļu plÄnoÅ”anas tirgus LatvijÄ atrodas attÄ«stÄ«bas stÄvoklÄ« un lÄ«dz ar to ir grÅ«ti prognozÄjams. TajÄ notiekoÅ”ie darÄ«jumi ieÅem ievÄrojamu vietu valsts kopÄjÄ finansu tirgÅ«. Nodokļu plÄnoÅ”anas tirgus attÄ«stÄ«bas pamatÄ ir ekonomiskÄ stabilitÄte valstÄ«, sakÄrtota likumdoÅ”ana, nodroÅ”inÄÅ”anÄs pret nelabvÄlÄ«gu faktoru ietekmi, kÄ arÄ« paÅ”mÄju un Ärzemju kapitÄla piesaiste.The name of master thesis is āDesign and inculcation of modern technologies of tax planning, protection of assets and information in enterprises in Latvia and worldwide for tax optimization purposesā.
Main goal of this master thesis is to do the research of low tax jurisdictions essence, describe important solutions, to show benefit of inculcation of modern technologies of tax planning as well as to analyze the connected problems. Second goal is to describe the development tendencies of modern tax planning in Latvia and worldwide and to describe directions of development of tax planning services.
Master thesis consists of the introduction; four produced parts; the conclusions and proposals. The essence of low tax jurisdictions and development tendency in world market were conducted in the first part of the master thesis. The business sectors, corporate functions and working schemes of law tax jurisdictions were investigated in the second part of the master thesis. Technology and schemes of protection of assets and information have been analyzed in the third part of the master thesis. In the fourth part of the master thesis have been produced the new structure of international holding companies and have been found the advantages of holding companies for tax optimization purposes.
The main conclusion of this master thesis is ā the market of tax planning services in Latvia is developing and as a result is hardly predictable. But despite this fact, tax planning take an important part in countryās financial market. The modern tax planning services development is based and depends on countryās economical situation, the legislation and the level of insurance from influence of undesirable factors as well as local and foreign capital attraction