| 1. |
- Gudmundsson, Jon Tomas, 1965-, et al.
(författare)
-
Oxygen discharges diluted with argon : dissociation processes
- 2007
-
Ingår i: Plasma sources science & technology. - : Institute of Physics Publishing (IOPP). - 0963-0252 .- 1361-6595. ; 16:2, s. 399-412
-
Tidskriftsartikel (refereegranskat)abstract
- We use a global (volume averaged) model to study the dissociationprocesses and the presence of negative ions and metastable species in a lowpressure high density O2/Ar discharge in the pressure range 1–100 mTorr.The electron density and the fractional dissociation of the oxygen moleculeincreases with increased argon content in the discharge. We relate thisincrease in fractional dissociation to an increase in the reaction rate forelectron impact dissociation of the oxygen molecule which is due to theincreased electron temperature with increased argon content in thedischarge. The electron temperature increases due to higher ionizationpotential of argon than for molecular and atomic oxygen. We find thecontribution of dissociation by quenching of the argon metastable Armbymolecular oxygen (Penning dissociation) to the creation of atomic oxygen tobe negligible. The negative oxygen ion O−is found to be the dominantnegative ion in the discharge. Dissociative attachment of the oxygenmolecule in the ground state O2(X3−g)and in particular the metastableoxygen molecule O2(a1g)are the dominating channels for creation of thenegative oxygen ion O−.(Some figures in this article are in colour only in the electronic version)
|
|
| 2. |
- Helmersson, Ulf, et al.
(författare)
-
Ionized physical vapor deposition (IPVD): A review of technology and applications
- 2006
-
Ingår i: Thin Solid Films. - : Elsevier. - 0040-6090 .- 1879-2731. ; 513:1-2, s. 1-24
-
Tidskriftsartikel (refereegranskat)abstract
- In plasma-based deposition processing, the importance of low-energy ion bombardment during thin film growth can hardly be exaggerated. Ion bombardment is an important physical tool available to materials scientists in the design of new materials and new structures. Glow discharges and in particular the magnetron sputtering discharge have the advantage that the ions of the discharge are abundantly available to the deposition process. However, the ion chemistry is usually dominated by the ions of the inert sputtering gas while ions of the sputtered material are rare. Over the past few years, various ionized sputtering techniques have appeared that can achieve a high degree of ionization of the sputtered atoms, often up to 50 % but in some cases as much as approximately 90%. This opens a complete new perspective in the engineering and design of new thin film materials. The development and application of magnetron sputtering systems for ionized physical vapor deposition (IPVD) is reviewed. The application of a secondary discharge, inductively coupled plasma magnetron sputtering (ICP-MS) and microwave amplified magnetron sputtering, is discussed as well as the high power impulse magnetron sputtering (HIPIMS), the self-sustained sputtering (SSS) magnetron, and the hollow cathode magnetron (HCM) sputtering discharges. Furthermore, filtered arc-deposition is discussed due to its importance as an IPVD technique. Examples of the importance of the IPVD-techniques for growth of thin films with improved adhesion, improved microstructures, improved coverage of complex shaped substrates, and increased reactivity with higher deposition rate in reactive processes are reviewed.
|
|
| 3. |
- Magnus, Fridrik, et al.
(författare)
-
Digital Smoothing of the Langmuir Probe I-V Characteristic
- 2008
-
Ingår i: Review of Scientific Instruments. - : American Institute of Physics (AIP). - 0034-6748 .- 1089-7623. ; 79:7
-
Tidskriftsartikel (refereegranskat)abstract
- Electrostatic probes or Langmuir probes are the most common diagnostic tools in plasma discharges. The second derivative of the Langmuir probe I-V characteristic is proportional to the electron energy distribution function. Determining the second derivative accurately requires some method of noise suppression. We compare the Savitzky-Golay filter, the Gaussian filter, and polynomial fitting to the Blackman filter for digitally smoothing simulated and measured I-V characteristics. We find that the Blackman filter achieves the most smoothing with minimal distortion for noisy data.
|
|
| 4. |
|
|
| 5. |
|
|
