Provided is a multi-negative differential resistance device. The multi-negative differential resistance device includes a first negative differential resistance device and a second negative differential resistance device connected in parallel with the first negative differential resistance device, and a peak and a valley of the first negative differential resistance device and a peak and a valley of the second negative differential resistance device are synthesized, and, thus, the multi-negative differential resistance device has two peaks and two valleys.

An integrated neuron circuit structure comprising at least one thin-film resistor, one Metal Insulator Metal capacitor and one Negative Differential Resistance device.

A rectifier is provided for converting an oscillating electromagnetic field into a direct current and comprises an electrically conductive antenna layer configured to absorb electromagnetic radiation, an electrically conductive mirror layer configured to provide an electromagnetic mirror charge of the antenna layer, an electrically insulating tunnel barrier layer positioned between the antenna layer and the mirror layer, and an electronic circuit electrically connected between the conductive mirror layer and the conductive antenna layer. The rectifier employs a metamaterial configuration for room temperature rectification of radiation in regions of the electromagnetic spectrum comprising the MWIR and LWIR regions. Methods for use of the rectifier in rectifying and detecting radiation are described.

A system and method of etching a semiconductor device are provided. Etching solution is sampled and analyzed by a monitoring unit to determine a concentration of components within the etching solution, such as an oxidant concentration. Then, based upon such measurement, a makeup amount of the components may be added be a makeup unit to the etching solution to control the concentration of the components within the etching system.

A semiconductor package structure includes a conductive structure, a semiconductor element disposed on and electrically connected to the conductive structure, a supporting structure, an encapsulant, and a metal layer. The supporting structure is disposed on the conductive structure and surrounds the semiconductor element. The encapsulant covers the semiconductor element. The metal layer is disposed on or embedded in the encapsulant.