Provided is a semiconductor device manufacturing method comprising: forming an impurity region including a first impurity on a semiconductor wafer; annealing the semiconductor wafer in a state where a lower surface of the semiconductor wafer is supported; and removing at least a part of the impurity region by removing a region including the lower surface of the semiconductor wafer. The first impurity may be oxygen. After the annealing, a maximum value of a concentration of the first impurity in the impurity region may be equal to or greater than 1×10.sup.18/cm.sup.3.

A semiconductor wafer of single-crystal silicon has an oxygen concentration per new ASTM of not less than 5.0×10.sup.17 atoms/cm.sup.3 and not more than 6.5×10.sup.17 atoms/cm.sup.3; a nitrogen concentration per new ASTM of not less than 1.0×10.sup.13 atoms/cm.sup.3 and not more than 1.0×10.sup.14 atoms/cm.sup.3; a front side having a silicon epitaxial layer wherein the semiconductor wafer has BMDs whose mean size is not more than 10 nm determined by transmission electron microscopy and whose mean density adjacent to the epitaxial layer is not less than 1.0×10.sup.11 cm.sup.−3, determined by reactive ion etching after having subjected the wafer covered with the epitaxial layer to a heat treatment at a temperature of 780° C. for a period of 3 h and to a heat treatment at a temperature of 600° C. for a period of 10 h.

A method for manufacturing an epitaxial wafer by forming a single crystal silicon layer on a wafer containing a group IV element including silicon, the method including the steps of: removing a natural oxide film on a surface of the wafer containing the group IV element including silicon in an atmosphere containing hydrogen; forming an oxygen atomic layer by oxidizing the wafer after removing the natural oxide film; and forming a single crystal silicon by epitaxial growth on the surface of the wafer after forming the oxygen atomic layer, where a planar density of oxygen in the oxygen atomic layer is set to 4×10.sup.14 atoms/cm.sup.2 or less. A method for manufacturing an epitaxial wafer having an epitaxial layer of good-quality single crystal silicon while also allowing the introduction of an oxygen atomic layer in an epitaxial layer stably and simply.

A silicon wafer having a layer of oxygen precipitates and method of manufacturing thereof wherein the wafer exhibiting robustness characterized as having a ratio of a first average density from a first treatment that to a second average density from a second treatment is between 0.74 to 1.02, wherein the first treatment includes heating the wafer or a portion of the wafer at about 1150° C. for about 2 minutes and then between about 950 to 1000° C. for about 16 hours, and the second treatment includes heating the wafer or a portion of the wafer at about 780° C. for about 3 hours and then between about 950 to 1000° C. for about 16 hours. The wafer exhibits heretofore unattainable uniformity wherein a ratio of an oxygen precipitate density determined from any one cubic centimeter in the BMD layer of the wafer to another oxygen precipitate density from any other one cubic centimeter in the BMD layer of the wafer is in a range of 0.77 to 1.30.

Methods for preparing epitaxial wafers are disclosed. The methods may involve control of the (i) a growth velocity, v, and/or (ii) an axial temperature gradient, G, during the growth of an ingot segment such that v/G is less than a critical v/G. An epitaxial layer is deposited on a substrate sliced from the silicon ingot.

A method produces a single-crystal silicon semiconductor wafer. A single-crystal silicon substrate wafer is double side polished. A front side of the substrate wafer is chemical mechanical polished (CMP). An epitaxial layer of single-crystal silicon is deposited on the front side of the substrate wafer. A first rapid thermal anneal (RTA) treatment is performed on the coated substrate wafer at 1275-1295° C. for 15-30 seconds in argon and oxygen, having oxygen of 0.5-2.0 vol %. The coated substrate wafer is then cooled at or below 800° C., with 100 vol % argon. A second RTA treatment is performed on the coated substrate wafer at a 1280-1300° C. for 20-35 seconds in argon. An oxide layer is removed from a front side of the coated substrate wafer. The front side of the coated substrate wafer is polished by CMP.

A substrate made of doped single-crystal silicon has an upper surface. A doped single-crystal silicon layer is formed by epitaxy on top of and in contact with the upper surface of the substrate. Either before or after forming the doped single-crystal silicon layer, and before any other thermal treatment step at a temperature in the range from 600° C. to 900° C., a denuding thermal treatment is applied to the substrate for several hours. This denuding thermal treatment is at a temperature higher than or equal to 1,000° C.

Epitaxially coated semiconductor wafers of monocrystalline silicon comprise a p.sup.+-doped substrate wafer and a p-doped epitaxial layer of monocrystalline silicon which covers an upper side face of the substrate wafer; an oxygen concentration of the substrate wafer of not less than 5.3×10.sup.17 atoms/cm.sup.3 and not more than 6.0×10.sup.17 atoms/cm.sup.3; a resistivity of the substrate wafer of not less than 5 mΩcm and not more than 10 mΩcm; and the potential of the substrate wafer to form BMDs as a result of a heat treatment of the epitaxially coated semiconductor wafer, where a high density of BMDs has a maximum close to the surface of the substrate wafer.

A method produces a single-crystal silicon semiconductor wafer. A single-crystal silicon substrate wafer is double side polished. A front side of the substrate wafer is chemical mechanical polished (CMP). An epitaxial layer of single-crystal silicon is deposited on the front side of the substrate wafer. A first rapid thermal anneal (RTA) treatment is performed on the coated substrate wafer at 1275-1295° C. for 15-30 seconds in argon and oxygen, having oxygen of 0.5-2.0 vol %. The coated substrate wafer is then cooled at or below 800° C., with 100 vol % argon. A second RTA treatment is performed on the coated substrate wafer at a 1280-1300° C. for 20-35 seconds in argon. An oxide layer is removed from a front side of the coated substrate wafer. The front side of the coated substrate wafer is polished by CMP.

Provided is a method of manufacturing an epitaxial wafer, which includes vapor-phase growing an epitaxial layer on a substrate W placed on a susceptor 3 in a state where an upper surface 4b1 of a lift pin 4 inserted in a through-hole H of the susceptor 3 retracts or projects with respect to an upper opening H1a of the through-hole H. A level difference D from the upper surface 4b1 of the lift pin 4 to the opening H1a of the through-hole H is measured with laser light, and outputs, during epitaxial growth, of heaters 9 located above and beneath the susceptor 3 are adjusted on the basis of the measured level difference D. Thus, a method of manufacturing an epitaxial wafer, which facilitates adjustment of the outputs of the heat sources during epitaxial growth, is provided.