The present application provides a method for verification of conductivity type of a silicon wafer. The method comprises measuring the resistivity of the silicon wafer to obtain a first resistivity, placing the silicon wafer under atmosphere of air for a predicted time period, measuring the resistivity of the silicon wafer to obtain a second resistivity, and determining conductivity type of the silicon wafer by comparing the first resistivity and the second resistivity. The method can be applied to a silicon wafer having a high resistivity such as higher than 500 ohm.sup.-cm to rapidly and accurately determine conductivity type of the silicon wafer. Advantages of the method of the present application include accurate test results, easy operation, simple device requirement, and reduced cost.

Provided is a semiconductor device including: a semiconductor substrate having a drift region of a first conductivity type; and a buffer region of the first conductivity type provided between the drift region and a lower surface of the semiconductor substrate and having a higher doping concentration than the drift region. The buffer region has two or more helium chemical concentration peaks arranged at different positions in a depth direction of the semiconductor substrate.

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 gettering property evaluation apparatus includes a gettering determination unit and a chuck table. The gettering determination unit has a laser beam applying unit for applying a laser beam to a wafer, and a transmission-reception unit for applying a microwave to the wafer and receiving the microwave reflected by the wafer. The gettering determination unit determines whether or not a gettering layer including a grinding strain generated by grinding the wafer has a gettering property. The chuck table holds the wafer on a holding surface. The chuck table has a conductive nonmetallic porous member constituting the holding surface and having a property of reflecting or absorbing the microwave, and a base member provided with a negative pressure transmission passage for transmitting a negative pressure to the nonmetallic porous member.

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 temporary substrate, which is detachable at a detachment temperature higher than 1000° C. comprises: a semiconductor working layer extending along a main plane, a carrier substrate, an intermediate layer having a thickness less than 20 nm arranged between the working layer and the carrier substrate, a bonding interface located in or adjacent the intermediate layer, gaseous atomic species distributed according to a concentration profile along the axis normal to the main plane, the atoms remaining trapped in the intermediate layer and/or in an adjacent layer of the carrier substrate with a thickness less than or equal to 10 nm and/or in an adjacent sublayer of the working layer with a thickness less than or equal to 10 nm when the temporary substrate is subjected to a temperature lower than the detachment temperature.

Methods for forming a trench structure with passivated surfaces. In some embodiments, a method of forming a trench structure may include etching a trench into a substrate material of the substrate, forming an oxide layer on surfaces of the trench using a dry oxide process at a temperature of less than approximately 450 degrees Celsius, selectively removing the oxide layer from surfaces of the trench, and forming a passivation layer on surfaces of the trench to form a homogeneous passivation region as part of the substrate material using a low temperature process of less than approximately 450 degrees Celsius.

Methods for forming a trench structure with passivated surfaces. In some embodiments, a method of forming a trench structure may include etching a trench into a substrate material of the substrate, forming an oxide layer on surfaces of the trench using a dry oxide process at a temperature of less than approximately 450 degrees Celsius, selectively removing the oxide layer from surfaces of the trench, and forming a passivation layer on surfaces of the trench to form a homogeneous passivation region as part of the substrate material using a low temperature process of less than approximately 450 degrees Celsius.

An integrated circuit (IC) substrate manufacturing process provides time-dependent device characteristic variation due to hydrogen absorption by including one or more gettering layers near the devices that would otherwise absorb hydrogen and exhibit the variation as the hydrogen migrates in the devices. The method includes forming or mounting the devices on a top surface of the semiconductor wafer in die areas of the substrate, forming semiconductor structures in the semiconductor die areas, forming a getter layer above or adjacent to the devices in the die areas, and processing the wafer with one or more processes exposing the wafer to vapor having a hydrogen content, whereby an amount of hydrogen absorbed by the devices is reduced by presence of the getter layer. The method produces wafers including semiconductor dies with reduced hydrogen absorption by the devices and packaged ICs including the dies.