METHOD FOR MANUFACTURING A MONOCRYSTALLINE STRUCTURE

• Main Authors: VALLIER, Laurent, BESSON, Pascal, HARTMANN, Jean-Michel, LOUP, Virginie, RAYNAL, Pierre-Edouard
• Format: Patent
• Language: English; French; German
• Published: 28.08.2024
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR; BASIC ELECTRIC ELEMENTS; CHEMISTRY; CRYSTAL GROWTH; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; METALLURGY; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; SEMICONDUCTOR DEVICES; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

A substrate is provided with a monocrystalline silicon-germanium layer with a first surface covered by a protective oxide obtained by wet process and having a degradation temperature. The protective oxide is transformed into fluorinated salt which is then eliminated. The substrate is placed in a processing chamber at a lower temperature than the degradation temperature and is subjected to a temperature ramp up to a higher temperature than the degradation temperature. The first surface is annealed in a hydrogen atmosphere devoid of silicon, germanium and precursors of the materials forming the target layer. When the temperature ramp is applied, a silicon precursor is inserted in the processing chamber between a loading temperature and the degradation temperature to deposit a monocrystalline buffer layer. A mono-crystalline target layer is deposited by chemical vapour deposition.