Investigation of impurity effect on re-crystallization process in heavily implanted silicon carbide

研究了磷离子注入4 H-SiC（112-0）的再结晶速率与杂质浓度的关系。本研究中使用的样品是p型4 H-SiC（112-0）。将磷离子多重注入以形成厚度为200 nm且磷浓度分别为1 × 10 - 4<20>、4 × 10 - 4<20>和1 × 10 - 4<21>/cm-3的注入层。用红外热像退火炉和黑色SiC坩埚对注入样品进行了660 ~ 720 ℃的等温退火。4 H-SiC（11-20）中P离子诱导的非晶层的再结晶速率随着激活能的增加而增加，6 H-SiC（11-20）和（1-100）中Ar离子诱导的非晶层的再结晶速率也随着激活能的增加而增加。当P浓度从1 × 10 ~（<20>13）/cm ~ 3增加到1 × 10 <21>~（13）/cm ~ 3时，再结晶速率从3.5 nm/min增加到约5 nm/min，而Ar气诱导非晶层的再结晶速率为1.5 nm/min。对于Al到SiC的注入的情况，确定了类似的效果。

We investigated that the impurity concentration dependence of the recrystallization rate of the phosphorus implanted 4H-SiC(112-0). Samples used in the present study were p-type 4H-SiC(112-0). The phosphorus ions were multiply implanted to form the implantation layer with the thickness of 200 nm and the phosphorus concentration of 1 x 10^<20>, 4 x 10^<20>, and 1 x 10^<21>/cm^3, respectively. The isothermal annealing of the implanted samples were performed at the temperature range from 660 to 720 ℃ in Ar gas flow using an infrared image annealer with a black SiC crucible. The recrystallization rate of the P ion implantation-induced amorphous layer in 4H-SiC(11-20) increases with an activation energy of 3.4 eV as well as the case of the Ar ion implantation-induced amorphous layer in 6H-SiC(11-20) and (1-100). As the P concentration is increased from 1 x 10^<20> to 1 x 10^<21> /cm^3, the recrystallization rate is enhanced from 3.5 to about 5nm/min, while the recrystallization rate for Ar implantation-induced amorphous layer was 1.5 nm/min. It is suggested that the recrysallizatioin process is enhanced by the presence of the substitutional impurity at the a/c interface during the recrystallization. The similar effect is identified for the case of the implanted of Al to SiC.