Abrupt Lateral-Source Heterostructures with Relaxed/Strained Layers for Ballistic Complementary Metal Oxide Semiconductor Transistors Fabricated by Local O+ Ion-Induced Relaxation Technique of Strained Substrates

We have experimentally studied an abrupt lateral-relaxed/strained layer heterojunction for ballistic complementary metal oxide semiconductor (CMOS) transistors, which is fabricated by a local O⁺ ion-induced relaxation technique for strained semiconductors on a buried oxide layer. We have demonstrated that strained substrates in various conditions are suddenly relaxed at a critical recoil energy of O⁺ ions at the strained semiconductor/buried oxide layer interface. Moreover, after O⁺ ion implantation into strained substrates with a SiO₂ mask as well as post-annealing processes, we have successfully formed lateral relaxed/strained Si layers with an abrupt strain distribution at the mask edge, according to Raman spectroscopy analysis of implanted strained substrates. In addition, strained Si layers even under the 50-nm length stripe SiO₂ mask region can still keep over 60% of the strain value in strained Si layers with a large area.