Making the Wafer
The process
-A seed crystal is suspended in a molten bath of silicon
-It is slowly pulled up and grows into an ingot of silicon
-The ingot is removed and ground down to diameter
-The end is cut off, then thin silicon wafers are sawn off (sliced) and polished
Epitaxy
The growth of an ultra-pure layer of crystalline silicon
Approx 3% of wafer thickness
Contaminant-free
PE CVD
PE CVD공정은 Plasma etching 이 사용되기 이전부터 반도체 금속배선의 보호막인 SiN과 SiO2를 저온에서 증착할 수 있는 새로운 생성원으로 소개
PE CVD기술은 SiO2와 SiN 박막 형성 뿐만 아니라 최근에는 천이금속이나 천이금속 실리사이드 형성에도 널리 사용
PE CVD의 박막 형성 mechanism
Plasma 에서 이
process of deposition of oxide layer. When the charges exist in between the substrate and interface, the value of Vfb and C-V curve will shift by amount of the charge divided by Cox of Ci. The amount of shifting decreases as the position of fiexed charges is far from interface on the substrate and shifting will not exist any more when it is located on the interface between metal and interface. Mo
○ PECVD
∙ What is PECVD?
⇒ Radio frequency(RF) is used to induce plasma in the deposition gas.
⇒ This results in a higher deposition rate at relatively low temperatures.
⇒ With the plasma enhanced CVD process is the deposition at temperature around 300℃ allows.
⇒ The temperature will be through encouragement of a plasma with high frequency electric fields triggered.
General Process of 3D printing
FDM - Fused Deposition Molding
FDM works on an "additive" principle by laying down material in layers.
The model is produced by extruding small beads of thermoplastic material to form layers as the material hardens immediately after extrusion from the nozzle.
The nozzle can be moved in both horizontal and vertical directions by a numerically controlled mechanism