Abstract: A smoke alarm having a layered structure includes a case, a smoke detecting unit, and a layering plate. The smoke detecting unit is disposed in the case, and includes a smoke collecting box and a control module electrically connected to the smoke collecting box. The layering plate is disposed in the case. The layering plate defines an upper layer space and a lower layer space in the case, the upper layer space is a smoke guiding space, and the smoke collecting box is accommodated in the upper layer space to facilitate smoke-containing air to flow to the smoke collecting box. The lower layer space is a module mounting space, and the control module is accommodated in the lower layer space to facilitate mounting of a sub-module of the control module that is detachable.

Abstract: A one-time activation smoke alarm includes a smoke alarm body and a wall-hanging base. The smoke alarm body includes a case and a sliding sheet. An engaging recessed slot and a supporting protrusion platform are respectively formed on two sides of a bottom of the case. The sliding sheet is slidably disposed on the supporting protrusion platform, and a front end of the sliding sheet has a pressed protrusion portion that extends into the engaging recessed slot. An engaging protrusion platform is formed on the wall-hanging base, and at least one abutting protrusion portion protrudes outward from a periphery of the engaging protrusion platform. The engaging protrusion platform and the engaging recessed slot are capable of being engaged and fixed together such that the abutting protrusion portion abuts the pressed protrusion portion and the smoke alarm body activates a detection function.

Abstract: In a method for obtaining the equivalent oxide thickness of a dielectric layer, a first semiconductor capacitor including a first silicon dioxide layer and a second semiconductor capacitor including a second silicon dioxide layer are provided and a modulation voltage is applied to the semiconductor capacitors to measure a first scanning capacitance microscopic signal and a second scanning capacitance microscopic signal. According to the equivalent oxide thicknesses of the silicon dioxide layers and the scanning capacitance microscopic signals, an impedance ratio is calculated. The modulation voltage is applied to a third semiconductor capacitor including a dielectric layer to measure a third scanning capacitance microscopic signal. Finally, the equivalent oxide thickness of the dielectric layer is obtained according to the equivalent oxide thickness of the first silicon dioxide layer, the first scanning capacitance microscopic signal, third scanning capacitance microscopic signal, and the impedance ratio.

Abstract: In a method for obtaining the equivalent oxide thickness of a dielectric layer, a first semiconductor capacitor including a first silicon dioxide layer and a second semiconductor capacitor including a second silicon dioxide layer are provided and a modulation voltage is applied to the semiconductor capacitors to measure a first scanning capacitance microscopic signal and a second scanning capacitance microscopic signal. According to the equivalent oxide thicknesses of the silicon dioxide layers and the scanning capacitance microscopic signals, an impedance ratio is calculated. The modulation voltage is applied to a third semiconductor capacitor including a dielectric layer to measure a third scanning capacitance microscopic signal. Finally, the equivalent oxide thickness of the dielectric layer is obtained according to the equivalent oxide thickness of the first silicon dioxide layer, the first scanning capacitance microscopic signal, third scanning capacitance microscopic signal, and the impedance ratio.