Defect control in advanced high-mobility substrates

emittance control in high power linacs

چکیده این پایان نامه به بررسی اثر سیم پیچ مغناطیسی و کاوه یِ خوشه گر با بسامد رادیویی بر هاله و بیرونگراییِ باریکه هایِ پیوسته و خوشه ایِ ذرات باردار در شتابدهنده های خطیِ یونی، پروتونی با جریان بالا می پردازد و راه حل هایی برای بهینه نگهداشتن این کمیتها ارایه می دهد. بیرونگرایی یکی از کمیتهای اساسی باریکه هایِ ذرات باردار در شتابدهنده ها است که تاثیر قابل توجهی بر قیمت، هزینه و کاراییِ هر شتابدهند...

High Mobility in N-Type GaN Substrates

AlGaN/GaN High-Electron-Mobility Transistors on Different Substrates

The performance ofaluminum gallium nitride/gallium nitride (AlGaN/GaN) high-electron-mobility transistors (HEMTS) diamond and silicon carbide (SiC) substrates is examined. Additionally, the temperature rise in similar devices on diamond and SiC substrates is reported. Recently, identical AlGaN/GaN HEMTs have been fabricated at Cornell NanoScale Science & Technology Facility (CNF) on diamond, bu...

High electron mobility in SiGelSi n-MODFET structures on sapphire substrates

For the first time, SiGe/Si n-Modulation Doped Field Effect Transistors (n-MODFET) structures have been grown on sapphire substrates. Room temperature electron mobility value of 1271 cm2N-sec at an electron carrier density (ne) of 1.6~10’2 cm2 was obtained. At 250 mK, the mobility increases to 13,313 cm2N-sec (ne=1.33~10’2 cm-2) and Shubnikov-de Haas oscillations appear, showing excellent confi...

Under-gate defect formation in Ni-gate AlGaN/GaN high electron mobility transistors

AlGaN/GaN high electron mobility transistors (HEMTs) represent a rapidly maturing technology plagued by reliability issues which are not well understood. One such issue is the relationship between gate leakage and the formation of reaction-based defects at the interface between the gate metal and the underlying epitaxial semiconductor layers. Here, the combination of chemical etching-based depr...