DLTS studies of defects produced in n-type silicon by hydrogen implantation at low temperature

摘要

Metastable defects are discovered in hydrogen-implanted n-type silicon.Hydrogen implantation was performed with the energy of 80 ke V to a dose of 2*10~(10) cm~(-2) at 109 K.After implantation,the sample temperature was raised to room temperature.DLTS measurements were carried out in the temperature range 80-290 K for fabricated diodes.When the sample is reverse-biased at 10V for 10 rnin at room temperature and then is cooled down to 80 K,three new peaks labeled EM1,EM2 and EM3 appear around 150,190 and 240 K,respectively.The introduction of metastable defects is found to be characteristic of low temperature implantation.We have evaluated properties of EMl in detail.EMI with thermal emission activation energy of 0.29 eV has a peak in concentration around the depth of 0.64 11 m,which corresponds to the projected range of 80 keV hydrogen.EMl is regenerated with the reverse bias applied around 270 K and is removed with the zero bias around 220 K.