Verfahren zum Bestimmen der Staerke einer einkristallin auf einem Traegerkristall aufgewachsenen, aus der Gasphase abgeschiedenen Schicht aus Silicium oder Germanium

摘要

944,972. Determination of the thickness of deposited monocrystalline layers. SIEMENS & HALSKE A.G. Oct. 17, 1962 [Oct.19, 1961], No.39248/62. Heading G1M. A method of determining the thickness of a monocrystalline layer of silicon or germanium deposited from the gaseous phase on to a heated parent crystal of silicon or germanium, comprises etching the surface of the deposited layer for a time such that a geometric figure produced by faulty crystal growth is made visible, measuring the length of a side of the geometric figure and calculating the thickness of the deposited layer from this measurement. Preferably a flaw-free (111) plane of the parent crystal is used for deposition and a flaw or flaws are made on this surface by touching it with a glass needle or by scratching with a glass needle. Alternatively a fine brush or a plug of cottonwool may be used to produce the flaws. The deposited layer develops from the produced flaws in the fan of equilateral triangles for a (111) plane. Other planes will give different geometrical figures. The surface of the deposited layer is etched with a mixture of chromic and hydrofluoric acids in aqueous solution so that the triangles become clearly visible. The side of the triangle is measured e.g. by a measuring microscope and the thickness of the deposited layer calculated by using an empirical formula.