Abstract: A semiconductor device including a semiconductor substrate having an upper surface and a lower surface is provided. In a depth direction connecting the upper and lower surfaces of the semiconductor substrate, a donor concentration distribution includes a first donor concentration peak at a first depth, a second donor concentration peak at a second depth between the first donor concentration peak and the upper surface, a flat region between the first donor concentration peak and the second donor concentration peak, and a plurality of donor concentration peaks between the first donor concentration peak and the lower surface. The second donor concentration peak has a lower concentration than the first donor concentration peak. The donor concentration distribution in the flat region is substantially flat. The thickness of the flat region in the depth direction is 10% or more of the thickness of the semiconductor substrate.

Abstract: Provided is a semiconductor apparatus including: a first peak of a hydrogen chemical concentration disposed on the lower surface side of the semiconductor substrate; and a flat portion disposed on the upper surface side of the semiconductor substrate with respect to the first peak, containing a hydrogen donor, and having a substantially (almost) flat donor concentration distribution in a depth direction. An oxygen contribution ratio indicating a ratio of an oxygen chemical concentration contributing to generation of the hydrogen donor in the oxygen chemical concentration of the oxygen ranges from 1×10?5 to 7×10?4. A concentration of the oxygen contributing to generation of the hydrogen donor in the flat portion is lower than the hydrogen chemical concentration. A hydrogen donor concentration in the flat portion ranges from 2×1012/cm3 to 5×1014/cm3.

Abstract: A semiconductor device includes a semiconductor substrate with an upper surface and a lower surface, including an n-type semiconductor region having a hydrogen containing region. A carrier concentration distribution representing a carrier concentration by a semi-logarithmic graph in the depth direction of the n-type semiconductor region includes a flat portion containing a first flat part and a second flat part located closer to the lower surface of the semiconductor substrate than the first plat part, and a slope located between the first flat part and the second flat part.

Abstract: Provided is a semiconductor device including a buffer region. Provided is a semiconductor device including: semiconductor substrate of a first conductivity type; a drift layer of the first conductivity type provided in the semiconductor substrate; and a buffer region of the first conductivity type provided in the drift layer, the buffer region having a plurality of peaks of a doping concentration, wherein the buffer region has: a first peak which has a predetermined doping concentration, and is provided the closest to a back surface of the semiconductor substrate among the plurality of peaks; and a high-concentration peak which has a higher doping concentration than the first peak, and is provided closer to an upper surface of the semiconductor substrate than the first peak is.

Abstract: A laser annealing method for a semiconductor device, includes: a first step of adding an impurity to a semiconductor substrate; and a second step of irradiating a region to which the impurity is added with a pulsed laser beam a plurality of times to anneal the semiconductor substrate. In the second step, a first region of a portion of the region to which the impurity is added is irradiated with the pulsed laser beam, and after a predetermined time interval, a second region adjacent to the first region is irradiated with the pulsed laser beam. The predetermined time interval is larger than a pulse interval of the pulsed laser beam.

Abstract: There is provided a semiconductor device, a hydrogen concentration distribution has a hydrogen concentration peak, a helium concentration distribution has a helium concentration peak, and a donor concentration distribution has a first donor concentration peak and a second donor concentration peak; the hydrogen concentration peak and the first donor concentration peak are located at a first depth, and the helium concentration peak and the second donor concentration peak are located at a second depth; each concentration peak has an upward slope; and a value which is obtained by normalizing a gradient of the upward slope of the second donor concentration peak by a gradient of the upward slope of the helium concentration peak is smaller than a value which is obtained by normalizing a gradient of the upward slope of the first donor concentration peak by a gradient of the upward slope of the hydrogen concentration peak.

Abstract: A method of applying to surfaces of component parts of an evaporator hydrophilic coatings which do not emit offensive odors under operating conditions, or at other times. The method provides coatings in which water glass and colloidal silica are attached to the surfaces in the form of solids in an amount of 0.010 to 0.066 g/m.sup.2.

Abstract: A heater (19) is disposed in an air flow duct (12) having an upper air outlet (22). An air filter (36) is disposed in a bypass duct (31) having an outlet (32) communicating with the upper outlet (22). Cool air flows into the bypass duct (31) from the air flow duct (12) upstream of the heater (19). Warm air is mixed with the cold air in the bypass duct (31) and is obtained either from the air flow duct (12) downstream of the heater (19) or is constituted by recirculated air from a vehicle passenger compartment.