IN THE NAME OF ALLAH, THE MOST MERCIFUL AND COMPASSIONATE

IN THE NAME OF ALLAH, THE MOST MERCIFUL AND COMPASSIONATE

Ion Beam Analysis of Diamond Thin Films Sobia Allah Rakha Experimental Physics Labs 04-03-2010

Outline Diamond Nanostructures Deposition of Diamond Nanostructures Ion Solid Interaction Elastic Recoil Detection (ERD) Analysis ERD Analysis of Diamond Films Conclusions

Diamond Nanostructures

Nanocrystalline Diamond (NCD) NCD films appear to be industrially acceptable alternative of monocrystalline diamonds. Having the outstanding properties of CVD diamond but ultra-smooth surface. Nano diamond is expected to be an effective FE material due to the NEA.

Results (HFCVD):( Deposition in H 2 rich CVD H 2 /CH 4 :98.5/1.5,Ts=1023 K, p= 30 Torr Sobia A. R. Yu G. J., Current Applied Physics 9 (2009) 698 702.

Results (HFCVD):( Deposition in H 2 rich CVD Microcrystalline Sample Sub-microcrystalline Sample Nanocrystalline Sample

Results (HFCVD):( Deposition in H 2 rich environment High nucleation rate limited the grain size within the range of few nanometers. C 2 dimer causes high nucleation rate which critically influences the growth parameters. C 2 dimer increases sharply by increasing filament temperature which resulted in nanosized crystallites.

Ion Solid Interaction

Ion Solid Interactions Nuclear Energy Loss Electronic Energy Loss An ion entering in a solid find atoms with electrons orbiting around in their orbits

Ion-atom interactions Secondary Ion Mass Spectrometry (SIMS) Secondary ions Ion beam Auger electrons X- rays Auger Electron Spectrometry (AES) Particle Induced X-ray Emission (PIXE) Elastic Recoil Detection (ERD) Backscattered particles Particle emission γ- rays Nuclear Reaction Analysis (NRA) Rutherford Backscattering Spectrometry (RBS) Ion-nucleus interactions Ion Beam Analysis

4UH Pelletron accelerator to procure the beam of charged particles, in LNAT (SINAP).

Elastic Recoil Detection

Elastic Recoil Detection A Convenient Method for Depth Profiling of Light Elements, Especially Hydrogen.

For better experimental statistic Samples should be of minimized surface roughness. Use highly collimated incident beams to minimize the loss of resolution caused by angular spread. Use Kapton and other polymers as range foil materials that have superior thickness uniformity.

Applications of ERDA For the quantitative information of hydrogen. Capable of Profiling 1H, 2D and 3T in one turn. To study the growth mechanism at the initial stage of diamond deposition by comparing the hydrogen concentration of the growth surface. To study incorporation of hydrogen both in bonded and non-bonded form present in non crystalline and defective regions of films.

ERD Analysis of Diamond Films

Schematic of Experimental Setup

Important parameters and capabilities of ERD Probe ion Ion energy Beam current Detector Depth resolution Range Foil He 1 4 MeV 1 1000 na SSBD (silicon surface barrier detector) ~ 700 Å. Mylar or other polymers Sensitivity ~ 0.5 atomic % to 0.1 atomic %. Analyzable depth ~ 6000 7000 Å

Results : Incorporation of Hydrogen in Diamond thin films 40 35 30 Channel 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 Determination of H: Simulation of data using QUARK-ERD Counts 25 20 15 10 5 0 0.811 1.811 2.811 Energy [ MeV ] 3.811 4.811 10 15 20 25 30 35 40 45 50 55 60 Channel 65 70 75 80 85 90 95 Simulation Experiment 100 105 110 115 120 125 130 135 130 120 10 15 20 25 30 35 40 45 50 55 60 Channel 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 70 110 100 60 90 50 80 Counts 40 30 Counts 70 60 50 40 20 30 10 20 10 0 0.811 1.811 2.811 Energy [ MeV ] 3.811 4.811 0 0.811 1.811 2.811 Energy [ MeV ] 3.811 4.811 Simulation Experiment Simulation Experiment

Results : Incorporation of Hydrogen in Diamond thin films Determination of H: Si standard with Known H content.

Results : Incorporation of Hydrogen in Diamond thin films Crystalline size (nm) 1 um ± 20 nm Hydrogen concentration vs. the crystalline size and I nd to I d ratios H (From Simulation) total concentration atoms/cm 3 H (From Standard) concentration atoms/cm 3 5.7 10 20 8 10 20 (0.8%) I nd / I d (Diamond Peak Position) 0.24 (1330) 300 nm ± 20 nm 50 nm ± 20 nm 1.2 10 21 1.3 10 21 (1.3%) 0.81 (1332) 3.0 10 21 3.3 10 21 (3.3%) 1.12 (1335) Sobia A.R., Diamond & Related Materials 18 (2009) 1247 1252.

Conclusions Diamond films in the grain size from micro to nanometer were synthesized in Hydrogen rich environments. Ion Solid Interactions. Elastic Recoil Detection Analysis of Diamond Films. Ion Beam Analysis Techniques proves helpful for the study of growth kinematics of the growing structures.

THANK YOU for your Attention