A kind of capacitive Si-based radiation detection device and its preparation method

Abstract

The invention provides a capacitance Si-based radiation detecting device, and a preparation method thereof. The detecting device comprises an Si substrate layer, wherein a buried oxide layer is set above the Si substrate layer; a metal fill area, a gate dielectric area, a Si thin layer, an ohmic contact injection area and an oxide isolation layer are set on the buried oxide layer from the center to the periphery; an ohmic contact area is set above the ohmic contact injection area; a gate metal electrode is set above the metal fill area. The detector has the advantages of high radiation sensitivity and induced charge capacity, low work gate voltage and high reliability. The method comprises the steps of growing the oxide isolation layer on a substrate; forming the ohmic contact injection area by doping light and heavy ions; forming the ohmic contact area via sputter deposition; forming a groove area via etching; forming the gate dielectric area via an atomic layer deposition process; forming a metal fill groove area via secondary etching; forming the metal fill area and the gate metal electrode via the Cu interconnection process. The method has the advantages of simpleness in process, good repeatability, low cost and easiness in integration with the fabrication process of the existing large-scale integrated circuit.

Description

technical field [0001] The invention belongs to the technical field of microelectronics and relates to semiconductor devices, in particular to a capacitive Si-based radiation detection device and a preparation method thereof. Background technique [0002] Radiation detectors are mainly used to measure various radiation environmental particles, such as photons, neutrons, alpha particles, beta particles and high-energy ions. Therefore, it has a wide range of applications in nuclear physics, medical treatment, biomedical occasions, and aerospace satellite detection and other fields. For example, in the field of space applications, it is necessary to measure the metering rate of particles in the space environment in real time, so as to ensure the normal operation of electronic equipment. [0003] MOS capacitive radiation dosimeter refers to a dosimeter made of semiconductor materials. Under radiation conditions, the gate oxide dielectric region of the device will generate indu...

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Problems solved by technology

The main problems of this type of RADFET device are as follows: 1) Due to the use of bulk silicon technology, the single event effect is not effectively isolated; 2) In order to suppress the degradation of the threshold voltage of the RADFET device after radiation, generally thicker The gate oxide thickness is too high, which causes the working voltage of the RADFET device to be too high; 3) The existing RADFET devices generally use SiO 2 (SiON) structure gate dielectric, which makes the sensitivity response low; 4) The working time of the existing RADFET device is short, which cannot meet the long-term recording of radiation information data; 5) Lack of protection devices, in the sudden high In a radiation environment, it is easy to cause burnout of MOS dose rate devices

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