MATERIAL ANALYSIS USING COMBINED ELASTIC RECOIL DETECTION AND RUTHERFORD ENHANCED RUTHERFORD BACKSCATTERING SPECTROMETRY

Three complimentary ion beam techniques will be combined in the analys is of oxide and nitride based materials, in particular BN/SiC and La0. 85Sr0.15CoO3. These materials can be synthesized over composition rang es which vary the physical and electrical properties, and therefore an accurate measure of the composition profiles is critical for controll ing these properties. Elastic recoil detection (ERD) revealed the comp osition of light elements from H to O, and Rutherford backscattering s pectrometry (RES) gave the composition of heavier elements (e.g., Si, Sr, Co and La). Enhanced Rutherford backscattering spectrometry (ERBS) complimented these techniques by utilizing enhanced cross sections, g reater than Rutherford, to increase the signal-to-noise ratio for anal ysis of mid-range elements O, C, and N. ERD with 24 MeV Si ions gave p rofiles for H, B, and N in thin films, and 30 MeV Si was able to profi le O in the top portion of heavier samples. Although 2.8 MeV He RES wo rked well for heavier elements, ERBS utilized He ions at 3.5 MeV for N analysis and 8.7 MeV for O analysis, because at these energies the cr oss sections are 2 and 22 times Rutherford, respectively. Also, the de pth of analysis was greater with ERBS because of the increased inciden t energy.