Crystallographic orientation of a cylindrical rcd of semiconductor material in a vapor deposition process to obtain a polygonal shaped rod

Claim 1

IN THE METHOD OF MAKING SEMICONDUCTOR MATERIAL BY DEPOSITION OF SAID SEMICONDUCTOR MATERIAL FROM A THERMALLY DECOMPOSABLE VAPOR SOURCE OF ATOMS OF SAID SEMICONDUCTOR MATERIAL UPON THE SURFACE OF A HEATED SEED ROD IN A CLOSED REACTION CHAMBER HAVING ENTRY PORT MEANS FOR THE ADMISSION OF THE FLOW OF GAS INCLUDING SAID VAPOR SOURCE, AND HAVING EXIT PORT MEANS FOR THE DISCHARGE OF THE SPENT GASES, THE IMPROVEMENT WHICH COMPRISES: (A) PROVIDING AS THE SEED ROD A SUBSTANTIALLY CYLINDRICAL ROD OF ESSENTIALLY MONOCRYSTALLINE SEMICONDUCTOR MATERIAL HAVING ITS LONGITUDINAL AXIS CRYSTALLOGRAPHICALLY ORIENTED WITH RESPECT TO THE MONOCRYSTALLINE STRUCTURE OF THE SEED ROD SO THAT THE PLANE PERPENDICULARLY TRANSVERSE TO THE LONGITUDINAL AXIS OF THE SEED ROD HAS LOW MILLER INDICES, WITH TWO OF SUCH INDICES EACH BEING THE INTEGER ONE, AND WITH THE SUM OF THE INTEGERS OF ALL THREE OF SUCH INDICES, DISREGARDING ANY NEGATIVE SIGNS, NOT EXCEEDING FOUR; (B) DEPOSITING SAID SEMICONDUCTOR MATERIAL IN MONOCRYSTALLINE FORM UPON SAID SEED ROD; AND (C) CONTINUING THE DEPOSITION EFFECTED BY THE PRECEDING STEP (B) UNTIL THE THUS FORMED MONOCRYSTAL OF SAID SEMICONDUCTOR MATERIAL EXHIBITS A POLYHEDRAL FORM ON A SECTION PERPENDICULARLY TRANSVERSE TO THE LONGITUDINAL AXIS OF SAID SEED ROD AND HAS A PLURALITY OF PLANAR OUTER SURFACES EACH ESSENTIALLY PARALLEL TO THE LONGITUDINAL AXIS OF SAID ROD, WITH AT LEAST THE PRINCIPAL SURFACES OF SUCH PLANAR SURFACES DISPOSED AROUND SUCH LONGITUDINAL AXIS AT A SUBSTANTIALLY EQUAL DISTANCE THEREFROM MEASURED ALONG LINES FROM SAID LONGITUDINAL AXIS PERPENDICUALR TO THE RESPECTIVE PLANAR SURFACES.