Abstract: A method for manufacturing a gray-tone mask that decreases the wavelength dependency with respect to an exposure wavelength under stable and simple film formation conditions. A reactive sputtering method that sputters a pure Cr target in an atmosphere of Ar and NO is used to form a Cr nitride film having a single-layer structure. Based on a plurality of different spectral transmittance curves obtained under a plurality of film formation conditions having different NO concentrations, a target concentration (intermediate value) for NO is obtained that sets the transmittance uniformity of the semi-transparent film to 1.0% or less in the range of 365 nm to 436 nm or 4.0% or less in the range of 300 nm to 500 nm. Then, a semi-transparent film is formed by using the NO target concentration.

Abstract: A control circuit 130 carries out ON/OFF control of a primary current flowing in an ignition coil in response to an input ignition control signal. The control circuit 130 and an insulated-gate bipolar power transistor (IGBT) 110 are integrated on a monolithic silicon substrate. The control circuit 130 includes a plurality of control circuit blocks of different functions formed on the silicon substrate. The circuit functions of the control circuit blocks are enabled and disabled by changing wiring patterns.

Abstract: An induction discharge system ignition device for an internal combustion engine includes a power switching device for producing a voltage to be applied to the primary winding of an induction coil. The secondary of the induction coil is connected to apply a high-tension voltage to a spark plug. The power switching device and the coil are particularly arranged to produce a voltage of at least 6.0 kV across the electrodes of the spark plug when the spark plug has a leakage of 100 k.OMEGA.. The turns ratio of the coil is, preferably, 70 or less.