Abstract: In a silicon carbide semiconductor film forming apparatus, first to third gasses are introduced into first to third separation chambers through first to third inlets, respectively. The first and second gasses are silicon raw material including gas and carbon raw material including gas, and the third gas does not include silicon and carbon. The first and second gasses are independently supplied to growth space through first and second supply paths extending from the first and second separation chambers, respectively. The third gas is introduced through a third supply path from the third separation chamber between the first and second gasses.

Abstract: It is an object of the present invention to provide a film-forming apparatus and a film-forming method that can prolong the lifetime of heaters used under high temperature conditions in an epitaxial growth technique. An inert gas discharge portion supplies an inert gas into the space containing the heater, gas is then discharged through the gas discharge portion without influence on the semiconductor substrate during film formation. It is therefore possible to prevent the reaction gas entering into the space containing the high-temperature heaters. This makes it possible to prevent a reaction between hydrogen gas contained in the reaction gas and SiC constituting the heaters. Therefore, it is possible to prevent carbon used as a base material of the heaters from being exposed due to the decomposition of SiC and then reacting with hydrogen gas. This makes it possible to prolong the lifetime of the heaters.

Abstract: A film-forming apparatus and method comprising a film-forming chamber for supplying a reaction gas into, a cylindrical shaped liner provided between an inner wall of the film-forming chamber and a space for performing a film-forming process, a main-heater for heating a substrate placed inside the liner, from the bottom side, a sub-heater cluster provided between the liner and the inner wall, for heating the substrate from the top side, wherein the main-heater and the sub-heater cluster are resistive heaters, wherein the sub-heater cluster has a first sub-heater provided at the closest position to the substrate, and a second sub-heater provided above the first sub-heater, wherein the first sub-heater heats the substrate in combination with the main-heater, the second sub-heater heats the liner at a lower output than the first sub-heater, wherein each temperature of the main-heater, the first sub-heater, and the second sub-heater is individually controlled.

Abstract: At the time of transporting a substrate into or from a space where a film formation process is performed, the space where the film formation process is performed, a space where a lower heater 16 is provided, and a space where an upper heater 19 is provided are made in an inert gas atmosphere.

Abstract: A film formation apparatus according to an embodiment includes: a film formation chamber performing film formation on a substrate; a cylindrical liner provided inside of a sidewall of the film formation chamber; a process-gas supply unit provided at a top of the film formation chamber and having a first gas ejection hole supplying a process gas to inside of the liner; a first heater provided outside the liner in the film formation chamber and heating the substrate from above; a second heater heating the substrate from below; and a shielding gas supply unit having a plurality of second gas ejection holes supplying a shielding gas to a position closer to a sidewall of the film formation chamber than a position of the first gas ejection hole.

Abstract: In a silicon carbide semiconductor film forming apparatus, first to third gasses are introduced into first to third separation chambers through first to third inlets, respectively. The first and second gasses are silicon raw material including gas and carbon raw material including gas, and the third gas does not include silicon and carbon. The first and second gasses are independently supplied to growth space through first and second supply paths extending from the first and second separation chambers, respectively. The third gas is introduced through a third supply path from the third separation chamber between the first and second gasses.

Abstract: A film-forming apparatus and method comprising a film-forming chamber for supplying a reaction gas into, a cylindrical shaped liner provided between an inner wall of the film-forming chamber and a space for performing a film-forming process, a main-heater for heating a substrate placed inside the liner, from the bottom side, a sub-heater cluster provided between the liner and the inner wall, for heating the substrate from the top side, wherein the main-heater and the sub-heater cluster are resistive heaters, wherein the sub-heater cluster has a first sub-heater provided at the closest position to the substrate, and a second sub-heater provided above the first sub-heater, wherein the first sub-heater heats the substrate in combination with the main-heater, the second sub-heater heats the liner at a lower output than the first sub-heater, wherein each temperature of the main-heater, the first sub-heater, and the second sub-heater is individually controlled.

Abstract: It is an object of the present invention to provide a film-forming apparatus and a film-forming method that can prolong the lifetime of heaters used under high temperature conditions in an epitaxial growth technique. An inert gas discharge portion supplies an inert gas into the space containing the heater, gas is then discharged through the gas discharge portion without influence on the semiconductor substrate during film formation. It is therefore possible to prevent the reaction gas entering into the space containing the high-temperature heaters. This makes it possible to prevent a reaction between hydrogen gas contained in the reaction gas and SiC constituting the heaters. Therefore, it is possible to prevent carbon used as a base material of the heaters from being exposed due to the decomposition of SiC and then reacting with hydrogen gas. This makes it possible to prolong the lifetime of the heaters.

Abstract: An SiC single crystal having at least one orientation region where a basal plane dislocation has a high linearity and is oriented to three crystallographically-equivalent <11-20> directions, and an SiC wafer and a semiconductor device which are manufactured from the SiC single crystal. The SiC single crystal can be manufactured by using a seed crystal in which the offset angle on a {0001} plane uppermost part side is small and the offset angle on an offset direction downstream side is large and growing another crystal on the seed crystal.

Abstract: In a manufacturing method of a silicon carbide single crystal, a seed crystal made of silicon carbide is prepared. The seed crystal has a growth surface and a stacking fault generation region and includes a threading dislocation that reaches the growth surface. The growth surface is inclined at a predetermined angle from a (0001) plane. The stacking fault generation region is configured to cause a stacking fault in the silicon carbide single crystal when the silicon carbide single crystal is grown. The stacking fault generation region is located at an end portion of the growth surface in an offset direction that is a direction of a vector defined by projecting a normal vector of the (0001) plane onto the growth surface. The seed crystal is joined to a pedestal, and the silicon carbide single crystal is grown on the growth surface of the seed crystal.

Abstract: When an SiC single crystal having a large diameter of a {0001} plane is produced by repeating a-plane growth, the a-plane growth of the SiC single crystal is carried out so that a ratio Sfacet (=S1×100/S2) of an area (S1) of a Si-plane side facet region to a total area (S2) of the growth plane is maintained at 20% or less.

Abstract: A manufacturing method of a SiC single crystal includes a first growth process and a re-growth process. In the first growth process, a first seed crystal made of SiC is used to grow a first SiC single crystal. In the re-growth process, a plurality of growth steps is performed for (n?1) times. In a k-th growth step, a k-th seed crystal is cut out from a grown (k?1)-th SiC single crystal, and the k-th seed crystal is used to grow a k-th SiC single crystal (n?2 and 2?k?n). When an offset angle of a growth surface of the k-th seed crystal is defined as ?k, at least in one of the plurality of growth steps, the offset angle ?k is smaller than the offset angle ?k-1.

Abstract: A silicon carbide single crystal includes nitrogen as a dopant and aluminum as a dopant. A nitrogen concentration is 2×1019 cm?3 or higher and a ratio of an aluminum concentration to the nitrogen concentration is within a range of 5% to 40%.

Abstract: An SiC single crystal includes a low dislocation density region (A) where the density of dislocations each of which has a Burgers vector in a {0001} in-plane direction (mainly a direction parallel to a <11-20> direction) is not more than 3,700 cm/cm3. Such an SiC single crystal is obtained by: cutting out a c-plane growth seed crystal of a high offset angle from an a-plane grown crystal; applying c-plane growth so that the density of screw dislocations introduced into a c-plane facet may fall in a prescribed range; cutting out a c-plane growth crystal of a low offset angle from the obtained c-plane grown crystal; and applying c-plane growth so that the density of screw dislocations introduced into a c-plane facet may fall in a prescribed range. An SiC wafer and a semiconductor device are obtained from such an SiC single crystal.

Abstract: A method for manufacturing a semiconductor wafer includes a carbon layer formation step, a through hole formation step, a feed layer formation step, and an epitaxial layer formation step. In the carbon layer formation step, a carbon layer (71) is formed on a surface of a substrate (70) made of polycrystalline SiC. In the through hole formation step, through holes (71c) are formed in the carbon layer (71) formed on the substrate (70). In the feed layer formation step, a Si layer (72) and a 3C—SiC polycrystalline layer (73) are formed on a surface of the carbon layer (71). In the epitaxial layer formation step, the substrate (70) is heated so that a seed crystal made of 4H—SiC single crystal is formed on portions of the surface of the substrate (70) that are exposed through the through holes (71c), and a close-spaced liquid-phase epitaxial growth of the seed crystal is caused to form a 4H—SiC single crystal layer.

Abstract: A film formation apparatus according to an embodiment includes: a film formation chamber performing film formation on a substrate; a cylindrical liner provided inside of a sidewall of the film formation chamber; a process-gas supply unit provided at a top of the film formation chamber and having a first gas ejection hole supplying a process gas to inside of the liner; a first heater provided outside the liner in the film formation chamber and heating the substrate from above; a second heater heating the substrate from below; and a shielding gas supply unit having a plurality of second gas ejection holes supplying a shielding gas to a position closer to a sidewall of the film formation chamber than a position of the first gas ejection hole.

Abstract: A manufacturing method of a SiC single crystal includes growing a SiC single crystal on a surface of a SiC seed crystal, which satisfies following conditions: (i) the SiC seed crystal includes a main growth surface composed of a plurality of sub-growth surfaces; (ii) among directions from an uppermost portion of a {0001} plane on the main growth surface to portions on a periphery of the main growth surface, the SiC seed crystal has a main direction in which a plurality of sub-growth surfaces is arranged; and (iii) an offset angle ?k of a k-th sub-growth surface and an offset angle ?k+1 of a (k+1)-th sub-growth surface satisfy a relationship of ?k<?k+1.

Abstract: A method for manufacturing a semiconductor wafer includes a carbon layer formation step, a through hole formation step, a feed layer formation step, and an epitaxial layer formation step. In the carbon layer formation step, a carbon layer (71) is formed on a surface of a substrate (70) made of polycrystalline SiC. In the through hole formation step, through holes (71c) are formed in the carbon layer (71) formed on the substrate (70). In the feed layer formation step, a Si layer (72) and a 3C—SiC polycrystalline layer (73) are formed on a surface of the carbon layer (71). In the epitaxial layer formation step, the substrate (70) is heated so that a seed crystal made of 4H—SiC single crystal is formed on portions of the surface of the substrate (70) that are exposed through the through holes (71c), and a close-spaced liquid-phase epitaxial growth of the seed crystal is caused to form a 4H—SiC single crystal layer.

Abstract: An SiC single crystal includes a low dislocation density region (A) where the density of dislocations each of which has a Burgers vector in a {0001} in-plane direction (mainly a direction parallel to a <11-20> direction) is not more than 3,700 cm/cm3. Such an SiC single crystal is obtained by: cutting out a c-plane growth seed crystal of a high offset angle from an a-plane grown crystal; applying c-plane growth so that the density of screw dislocations introduced into a c-plane facet may fall in a prescribed range; cutting out a c-plane growth crystal of a low offset angle from the obtained c-plane grown crystal; and applying c-plane growth so that the density of screw dislocations introduced into a c-plane facet may fall in a prescribed range. An SiC wafer and a semiconductor device are obtained from such an SiC single crystal.

Abstract: At the time of transporting a substrate into or from a space where a film formation process is performed, the space where the film formation process is performed, a space where a lower heater 16 is provided, and a space where an upper heater 19 is provided are made in an inert gas atmosphere.