Abstract: A scheme for depositing a private key used in the RSA cryptosystem which is capable of maintaining the private key more safely, without requiring a user to always carry around a storage medium. In this scheme, a private key of a user is divided into a first partial private key and a second partial private key at a user's entity, where the first partial private key is set to be maintained at the user's entity, while the second partial private key is deposited from the user's entity to the other entity. Then, the second partial private key is delivered from the other entity to the user's entity in response to a request from the user's entity, and the first partial private key maintained at the user's entity and the second partial private key delivered from the other entity are composed so as to obtain the private key to be used in a processing according to the RSA cryptosystem at the user's entity. This scheme can be generalized to a case of dividing the private key into a plurality of partial private keys.

Abstract: In an automatic thin-film measuring apparatus, the zero point of a precision balance is corrected according to directions from a data processing unit before and after the weight of a semiconductor substrate is measured, the surface temperature of the semiconductor substrate laid on a pan of the precision balance is measured, and the weight of the semiconductor substrate is measured when the surface temperature reaches a predetermined value. Furthermore, the cycle of variations in the zero point is found when the zero point is corrected, and the weight measurement of the semiconductor substrate is conducted during an integer multiple of the change cycle. Therefore, it is possible to enhance the precision of the weight measurement and its reproducibility and to shorten the measurement time without being influenced by low-frequency vibrations.

Abstract: The present invention is mainly characterized by providing an even surface of an interlayer insulating film for insulating and isolating an upper interconnection and a lower interconnection from each other. A lower interconnection layer is provided on a semiconductor substrate, having a pattern of stepped portions. A silicon type insulating film is provided on the semiconductor substrate so as to cover the lower interconnection layer. A silicon ladder resin film is filled in recessed portions of the surface of the silicon type insulating film for making even the surface of the silicon type insulating film. An upper interconnection layer electrically connected to the lower interconnection layer through a via hole is provided on the silicon type insulating film. The silicon ladder resin film has the structural formula: ##STR1## where R.sub.1 is at least one of a phenyl group and a lower alkyl group, R.sub.2 is at least one of a hydrogen atom and a lower alkyl group, and n is an integer of 20 to 1000.

Abstract: A single chamber apparatus for chemical vapor deposition of films on semiconductor substrates transported through the chamber. Heaters and a plurality of gas dispersing heads are disposed in the chamber for forming films by chemical vapor deposition. A cooling head is disposed between each adjacent pair of gas dispersing heads for cooling whereby the surface temperature of the substrates opposite the gas dispersing heads is substantially equal to that of the substrates located opposite the cooling heads.

Abstract: The rough ground rear surface 13b of a semiconductor wafer 11 is mirror-polished by localized irradiation with a focused laser beam 21. The wafer is moved relative to the beam, and the melt puddle formed by the beam thereafter recrystallizes at its trailing edge 24 to leave a mirror smooth rear surface 13c.