Experimental High Energy Physics & Plasma Etching

Transcription

1 Experimental High Energy Physics & Plasma Etching Samah M. Balouza Purdue University Nikhef Doctoral Interview 07/06/2017

2 Outlines Plasma Physics Research Experimental High Energy PhysicsResearch Samah Balouza - Nikhef Doctoral Interview 2

3 I- Plasma Physics Master Thesis: Modeling of Inductively Coupled Plasma (ICP)Etching RESEARCH OBJECTIVE: To study the plasma parameters that can generate high density plasma in order to enhance the directionality of the beam during the etching process of the microelectronic devices. Samah Balouza - Nikhef Doctoral Interview 3

4 METHODOLOGY Gaseous Electronic Conference RF Reference Cell (GEC): To compare results obtained by different research group. Stainless-steel chamber with parallel-plate electrodes having a diameter of 102 mm. Using COMSOL Multiphysics Simulation tool. Samah Balouza - Nikhef Doctoral Interview 4

5 RESULTS Electron Density (1/m3) Argon Ion Density (1/m3) Effect of Pressure The Figures illustrate the radial distributions of the argon ion density and electron density at the wafer surface respectively at different values of the pressure. The coil power was kept equal to 2000 W. 1.20E E E E E E E E E E E E E r/10^3 (m) 20 mtorr 25 mtorr 30 mtorr r/10^3 (m) 20 mtorr 25 mtorr 30 mtorr 35 mtorr 40 mtorr Electron densities at different pressure values. Argon ion densities at different pressure values. Samah Balouza - Nikhef Doctoral Interview 5

6 Electron Density (1/m3) Argon/Oxygen Mixture 1.20E E E E E E E E E r/10^3 (m) 30% O2 40% O2 50% O2 Electron density distributions at different oxygen concentrations. Samah Balouza - Nikhef Doctoral Interview 6

7 Results Summary I studied the pressure, power and the concentration of the mixture that affected the electron density distribution inside the reactor, the electron energy, and the ions density distribution. In pure argon, increasing the pressure led to increase in the electron density and the argon ion density distributions. By increasing the oxygen gas concentration in the mixture, the electron density decreases and the oxygen ion density increases. Samah Balouza - Nikhef Doctoral Interview 7

8 II- Experimental High Energy Physics: CMS Pixel Detector Working with the detector modules to calibrate the detector and the connected electronics. Detector modules, port cards, optical fibers, front end Controller, and front End driver. Pixel Detector Modules Front End Controller & Front End Driver Samah Balouza - Nikhef Doctoral Interview 8

9 Using XDAQ application to control the required tests to check the performance of the detector. Normal tests to check the efficiency of the detector and Sending/receiving data from the detector and the electronics. Detector Efficiency Scan-PixelAlive Samah Balouza - Nikhef Doctoral Interview 9

10 Pixel Detector Installation at CMS By 1 st of March, the new pixel detectors have been installed at CMS cavern and we are currently testing the whole detector after installation. Pixel Installation at CMS. Ref: Samah Balouza - Nikhef Doctoral Interview 10

11 Top Quark Analysis Spin Correlations Dilepton channel Feynman Diagram for top pair decay Histograms that represent the leptons and jets that have been selected from raw data that contains millions of events. Samah Balouza - Nikhef Doctoral Interview 11

12 Resistive Plate Chamber (RPC) EENP2 Marie Curie International Research Staff Exchange Scheme (IRSES). RPCs consist of two parallel plates, a positively-charged anode and a negativelycharged cathode, both made of a very high resistivity plastic material and separated by a gas volume. My research objective was testing the detector Performance by using the cosmic stand. Samah Balouza - Nikhef Doctoral Interview 12

13 Testing the detector performance by applying different HV values in the cosmic stand. HV Scan for 2 mm Gap HV Scan for 1.8 mm Gap Samah Balouza - Nikhef Doctoral Interview 13

14 CERN Summer School Project The research treated the development of the Micro-Pattern Gas Detectors, more specifically Gas Electron Multiplier (GEM) Detector. It consisted of two parts: Experimental work & Simulation work. In this project, the basic properties of the triple GEM detector were tested and measured, including energy calibration and energy resolution. Samah Balouza - Nikhef Doctoral Interview 14

15 GEM is one approach to the amplification. It is based on accelerating initial electrons with an electric field in order to use them to ionize more gas atoms. Electric field around GEM holes. The image is from Gas Detectors Development Group website 10X10 cm2 Triple GEM Detector Samah Balouza - Nikhef Doctoral Interview 15

16 Simulation of the Woven Mesh By using COMSOL Multiphysics Simulation code, I Calculated the electron transparency by simulating electron trajectories inside the detector. Electron Transparency is the ratio of the electrons that passing through the GEM hole. I studied the effect of changing the electric field on the electron transparency. Three Dimensions Woven Mesh Simulation with COMSOL Samah Balouza - Nikhef Doctoral Interview 16

17 Outreach Activities for CERN The Alphabet of the Universe. A CERN exhibit at the Bibliotheca Alexandrina, Alexandria, Egypt. CMS Virtual visits for Lebanon & Oman. Samah Balouza - Nikhef Doctoral Interview 17

18 My Research Experience! Working in an international organization CERN Experimental skills: state of the art electronics at CERN, graduation project, and modeling. Finding a research problem my master thesis Plasma applications; medical, etching, sputtering, implantation,. Asking experts in the field developed my communication skills. Samah Balouza - Nikhef Doctoral Interview 18

19 Thank You! 19

20 Back-Up Slides 20

21 IEEE-NPSS International Conference of Plasma Physics (ICOPS-2015) Samah Balouza - Nikhef Doctoral Interview 21

22 Electron Density (1/m3) Master Thesis: Model Validation Electron density versus pressure obtained from COMSOL simulation as compared to the experimental values at power 50 W and frequency 6.87 MHz. The experimental result obtained by V. A. Godyak, R. B. Piejak and B. M. Alexandrovich 2.5E+18 2E E+18 1E+18 5E Pressure (mtorr) COMSOL Experimental Electron density versus pressure Samah Balouza - Nikhef Doctoral Interview 22

23 Plasma Chemistry in Inductively Coupled Plasma Modeling Ar: Nobel Gas Increase the Number of Primary Electrons. O 2 : Quencher Gas Stabilize the Plasma. BUT, e + O 2 O 2 - Oxygen Attachment Reaction Samah Balouza - Nikhef Doctoral Interview 23

24 Electron Density (1/m3) The Effect of Coil Power In order to achieve the goal of maintaining the highest plasma density, the 30% oxygen concentration is selected as it gives the highest electron density. 1.60E E E E E E E E E r/10^3 (m) 600W 800W 1000W 1200W Electron density at different power values. Samah Balouza - Nikhef Doctoral Interview 24

25 - Graduation Project: Plasma Nitriding of Stainless Steel The main objective of nitriding the stainless steel is to improve the surface hardness by forming a hard nitrided layer. Material Sample: The AISI 304 Austenitic Stainless Steel. Vacuum Chamber (Stainless Steel 316) Cylindrical (20 cm x 10 cm). Schematic Illustration of the Plasma Nitriding Apparatus Samah Balouza - Nikhef Doctoral Interview 25

26 Results The parameters that changed: Hydrogen concentration and time of exposure. Methods used for testing the hardness: - Checking the nitrogen percentage by testing the alloy constituents before and after the exposure,e.g. XRD & Scanning Electron Microscope. - Mechanical Hardness Test (Vickers )test. Electron microscope scanning photo of Sample # 4T Samah Balouza - Nikhef Doctoral Interview 26

27 Graduation Project Challenges: The figure below shows that the edge of the DC nitrided sample has different colors as compared to the central area. This phenomenon, generally known as edge effect. It is one of the common problems for DC plasma nitriding. It has been explained in terms of the non-uniform sputtering and deposition during nitriding process. Leakage: minimum leakage means high purity. plasma. Material of the chamber should have high chemical and thermal stability. Surface of DC plasma nitrided samples Samah Balouza - Nikhef Doctoral Interview 27

28 Change of temperature with time for sample # 4T (150 minutes- 5% Hydrogen) Change of micro-hardness with time for sample # 4T (150 minutes - 5% Hydrogen) Samah Balouza - Nikhef Doctoral Interview 28

29 Graduation Project Awards Third Place in Best Graduation Project Competition 2010, Faculty of Engineering Alexandria University. Prof. Aly Mortada Award for the Best Graduation Project in 2010, Nuclear & Radiation Engineering Department, Alexandria University. The Project was partially funded by Intel-Egypt. Samah Balouza - Nikhef Doctoral Interview 29