Abstract: The present invention is a method of manufacturing polycrystalline silicon rods, wherein silicon is deposited onto a silicon core wire by a chemical vapor deposition (CVD) method such that a silicon member, which is cut out from a single-crystalline silicon ingot at an off-angle range of 5 to 40 degrees relative to a crystal habit line of the ingot, is used as the silicon core wire. The single-crystalline silicon ingot is preferably grown by a Czochralski (CZ) method or floating zone (FZ) method, such that the ingot preferably has an interstitial oxygen concentration of 7 ppma to 20 ppma. Silicon rods produced by this method are less likely to suffer a breakage caused by cleavage during the growth process of polycrystalline silicon during CVD, and exhibit improved FZ method success rates. The polycrystalline silicon rods produced by this method also have low impurity contamination and high single-crystallization efficiency.

Abstract: The present invention utilizes a silicon member (single-crystalline silicon rod), which is cut out from a single-crystalline silicon ingot which is grown by a CZ method or FZ method, as the core wire when manufacturing a silicon rod. Specifically, a planar silicon is cut out from a body portion which is obtained by cutting off a shoulder portion and a tail portion from a single-crystalline silicon ingot and is further cut into thin rectangles to obtain a silicon bar. In the case that the crystal growth axis orientation is <100>, there are four crystal habit lines, and the silicon bar is cut out such that the surface forms an off-angle ? in a predetermined range with the crystal habit line. The provided polycrystalline silicon rod has a low impurity contamination and high single-crystallization efficiency.

Abstract: A method for evaluating concentration of metal impurities contained in a silicon wafer, which comprises dropping concentrated sulfuric acid onto a surface of the silicon wafer to extract metal impurities solid-solubilized in the inside of the silicon wafer into the concentrated sulfuric acid, and chemically analyzing metal impurities contained in the concentrated sulfuric acid. The problem imposed on high sensitivity evaluation of metals contained in silicon bulk is, in addition to increase of sensitivity of analysis apparatus itself, how to extract metals contained in a silicon wafer to a surface and recover them. This problem can be solved by the method of the present invention.

Abstract: A method for evaluating concentration of metal impurities contained in a silicon wafer, which comprises dropping concentrated sulfuric acid onto a surface of the silicon wafer to extract metal impurities solid-solubilized in the inside of the silicon wafer into the concentrated sulfuric acid, and chemically analyzing metal impurities contained in the concentrated sulfuric acid. The problem imposed on high sensitivity evaluation of metals contained in silicon bulk is, in addition to increase of sensitivity of analysis apparatus itself, how to extract metals contained in a silicon wafer to a surface and recover them. This problem can be solved by the method of the present invention.

Abstract: A semiconductor pressure sensor chip has a pattern including first diffusion sections in which external connection contacts are formed. Resistors are connected to the first diffusion sections through second diffusion sections in a bridge circuit such that the distances between a contact and the second diffusion sections connected to a first diffusion section where the contact is disposed are equal. This arrangement reduces drift of the offset voltage with changes in temperature, thus providing a high precision semiconductor pressure sensor with an improved yield.

Abstract: A semiconductor chip with a gauge pressure sensor section and an absolute pressure sensor section is anodically bonded, in a vacuum, to a glass mount with an evacuated space between the absolute-pressure sensor section and the mated surface portion of the glass mount. The pressure to be measured is received by the reverse surface of the gauge pressure sensor section. Since no complicated package is mounted within the outer package, the assembly of the sensor is easy. Further, since the pressure sensor has two sensor sections, namely, the gauge pressure sensor section and the absolute pressure sensor section, the sensor can be used as an absolute pressure sensor of the reverse-surface pressure-receiving type.