SiGe channels can be used to boost the hole mobility and tailor the threshold voltage shift in advanced p-type Metal Oxide Semiconductor Field Effect Transistors. An efficient removal of SiGe oxides prior to the low temperature Selective Epitaxial Growth (SEG) of SiGe:B in the Sources/Drains regions of such devices is then mandatory. The H₂ bake that precedes SEG, carried out at temperatures typically lower than 650 °C to avoid islanding or shape change, requires a very efficient removal of surface contaminants (such as C, F, O…), beforehand. As germanium is very reactive in the air, Siconi® in-situ surface preparation schemes are likely to be of use on SiGe surfaces with such thermal budget constraints. Recently, a new surface preparation strategy based on i) a wet chemical oxide formation followed by ii) a standard NH₃/NF₃ remote plasma Siconi® process was evaluated. In order to use such a scheme for the fabrication of devices, we study here the impact of that surface preparation on the epitaxial regrowth of Si_0.60Ge_0.40 on Si_0.60Ge_0.40 films (in terms of oxygen removal efficiency, resulting morphology and so on). We show that such surface preparations yield drastically reduced interfacial contamination, with surfaces which can be rough after epitaxial re-growth, however. Thanks to an in-depth analysis of the interplay between surface preparation and growth parameters, an innovative process sequence is proposed that yields smooth, high-quality films.

SiGe通道可用于提高空穴迁移率并定制先进的p型金属氧化物半导体场效应晶体管中的阈值电压漂移。因此，必须强制在此类器件的源极/漏极区域进行低温SiGe：B的选择性外延生长（SEG）之前有效去除SiGe氧化物。H ₂在SEG之前进行的烘烤（通常在低于650°C的温度下进行，以避免出现孤岛或形状变化），需要事先非常有效地去除表面污染物（例如C，F，O…）。由于锗在空气中的反应性很强，因此Siconi®原位表面制备方案可能会在具有此类热预算约束的SiGe表面上使用。最近，评估了一种新的表面制备策略，该策略基于i）形成湿化学氧化物，然后ii）标准NH ₃ / NF ₃远程等离子体Siconi®工艺。为了使用这样的方案制造器件，我们在这里研究表面处理对Si _0.60 Ge _0.40在Si _0.60 Ge上外延再生的影响_0.40膜（就除氧效率，所得形态等而言）。我们表明，这样的表面处理可大大减少界面污染，但是在外延生长后表面可能会变粗糙。由于对表面制备和生长参数之间相互作用的深入分析，提出了一种创新的工艺流程，可生产出光滑，高质量的薄膜。