METHOD OF FORMING PROTECTIVE COATS FOR GRAPHITE SUBSTRATE HOLDERS AND DEVICE FOR METHOD EMBODIMENT Russian patent published in 2001 - IPC

FIELD: technology and equipment for making epitaxial silicon structures by method of settling from gaseous medium. SUBSTANCE: method consists in simultaneous heat treatment of entire substrate surface at temperature of 1300-1400 C in mixture and pressure of 1-10 mm Hg (1.43-13.3 10 Pa) during two hours, forming buffer coat at temperature of 900-1200 C and pressure of 1-30 mm Hg (1.33-39.9 10 Pa) in mixture of gases H₂ + HCl, 3-10 mcm thick and forming protective coat at temperature of 1200 to 1400 and pressure of 100-200 mm Hg (133-266 10 Pa), 10-20 mcm thick . Structurally, reactor of SiCl₄-C₂HCl₃ plant is made in form of dome with bearing flange. Hollow graphite substrate holder is located inside this dome. Graphite substrate holder is mounted on cylindrical quartz support. To obtain homogeneity of coat, graphite substrate holder is set in rotation in the coarse of settling. Lower Lateral surface of bearing flange is provided with hole for intensification of recirculation of vapor-and-gas mixture; vapor-and-gas mixture supply pipe unions are received by this hole. Three projections are provided over perimeter of upper surface of quartz support at equal distance relative to one another for placing the substrate holder. EFFECT: improved quality of epitaxial structures due to improved gas strength of protective coat and increased service life of substrate holders. 3 cl, 2 dwg