1188
Comprehensive Characterization of Dual Implanted Silicon after Electrical Activation Annealing

Tuesday, 31 May 2016
Exhibit Hall H (San Diego Convention Center)
W. S. Yoo (WaferMasters, Inc.), B. S. Jeon, S. D. Kim (SK hynix, Inc.), T. Ishigaki, and K. Kang (WaferMasters, Inc.)
Formation of low resistivity junctions is essential for fabricating high performance devices with advanced device modes. Significant effort has been expended, industry wide, to develop low resistivity junctions, over the years. However, the understanding of implant activation and implant damage recovery process is not sufficient. Development of noncontact implant residual damage monitoring techniques would be beneficial in process development for advanced node devices.  

In this study, we have investigated the effect of annealing temperature and time on the sheet resistance (Rs) of dual (P+ 1.0MeV, 4.0 x 1013 cm-2 + B+ 10keV, 3.0 x 1014cm-2)  implanted p--Si(100) wafers using a single wafer furnace-based (hot wall) rapid thermal annealing (RTA) system over a wide range of annealing conditions (350-800oC, 60-150s). Room temperature photoluminescence (RTPL) spectra were measured from all wafers under two different excitation wavelengths (650 and 785 nm) for additional clues on electrical properties of pn junctions, which cannot be obtained from the Rs measurements. Multiwavelength (457.9, 488.0 and 514.5 nm) Raman characterization was done on all wafers for additional insights on the degree of residual lattice damage, after RTA, under different conditions. After all on wafer measurements were completed, secondary ion mass spectroscopy (SIMS) dopant (P and B) depth profiling was done to assess dopant diffusion during the annealing process.

Rs values showed strong and systematic change with RTA temperature and time, as expected. RTPL spectra also showed large variations in intensity and wavelength distribution corresponding to the RTA temperature and time. Multiwavelength Raman characterization results showed gradual increase of intensity with the RTA temperature. Three regions of different Raman shift values, corresponding to the Si lattice stress and possibly the degree of residual implant damage, were also noted. SIMS P and B depth profiles did not show significant changes. Correlation among characterization results from various techniques and RTA conditions will be presented.