Novel delta doping technology with two or more dopants in silicon towards quantum information processing platform

提出了一种在硅中掺杂多种元素形成δ层的新技术，该技术采用两种方法相结合，利用特征表面结构对元素进行掺杂，并利用激光短退火将掺杂原子移至取代位活化。结果表明，选择Si（001）表面的铋原子纳米线作为掺杂源，纳米线中的Bi原子部分转变为Er原子，两种元素被掺杂到硅晶体的δ层中。混合激光退火，即激光曝光和炉退火的一系列组合，被证明可以激活δ掺杂在Si中的Bi给体。光致发光表明，密集的Bi原子被有效地激活，在靠近Si熔点的聚焦区域快速辐射加热时形成杂质带。由此产生的无意缺陷可以通过随后的390℃炉退火完全消除。非故意缺陷以g中心为特征，作为激光应用的新型光子材料而受到广泛关注。我们提出了一种新的方法，在具有高密度碳原子的表面区域产生g中心，其密度可达4×10^<19>cm^<-3>，高于碳原子在硅晶体中的溶解度极限。

A new technology that forms a δ layer with various elements dopants in the silicon, by combining two methods to dope elements with usage of characteristic surface structures and to move the doping atoms into substitutional sites to activate them by using a short laser annealing, was advocated. It was demonstrated that by choosing the bismuth atomic nanolines on the Si(001) surface as doping source, Bi atoms in the nanoline was partially changed into Er atoms, and both elements was doped into a δ layer in silicon crystal. Hybrid laser annealing, i.e., a serial combination of laser exposure and furnace annealing, is demonstrated to activate Bi donors that are δ-doped in Si. The photoluminescence reveals that the dense Bi atoms are activated so efficiently that an impurity band develops upon rapid radiation heating of the focused area close to the melting point of Si. The unintentional defects that are created thereby can be totally eliminated by subsequent furnace annealing at 390℃. The unintentional defects were characterized to be the G-centers and they get a lot of attention due to new photonic material for laser application. We propose a new method of creating G-centers in a surface region with highly dense carbon atoms of up to 4×10^<19>cm^<-3>, above the solubility limit of carbon atoms in silicon crystal.