High-frequency IMPATT diode mesa die structure and preparation method thereof

Abstract

The invention discloses a high-frequency IMPATT diode mesa die structure. The high-frequency IMPATT diode mesa die structure comprises a p+ conductive substrate; a mesa die is arranged on the top surface of the p+ conductive substrate. The high-frequency IMPATT diode mesa die structure is characterized in that a vertical through hole is formed in the center of the mesa die, so that the mesa die forms an annular circular truncated cone shape. During preparation, an n-type epitaxial layer, a p-type epitaxial layer and a p+ epitaxial layer are grown on an n+ silicon wafer; donor impurities n are doped into the n-type epitaxial layer, and acceptor impurities p are doped into the p-type epitaxial layer; a p+ electrode enhancement layer is prepared on the surface of the p+ epitaxial layer; the n+ silicon wafer is thinned; an n+ electrode enhancement layer is prepared on the thinned surface of the n+ silicon wafer; and corrosion is performed from the n+ electrode enhancement layer to the p+ epitaxial layer through photoetching and corrosion processes according to the design pattern of the mesa die to obtain the high-frequency IMPATT diode mesa die structure. The structure can well reduce additional equivalent resistance introduced by a skin effect in a high-frequency working state of a device, increase the output power of the device in the high-frequency working state, and improve the reliability of the device.

Description

technical field [0001] The invention relates to the technical field of millimeter-wave solid-state devices, in particular to a high-frequency IMPATT diode mesa die structure and a preparation method. Background technique [0002] Millimeter wave / terahertz is a fast-growing interdisciplinary subject. The academic value of scientific research and the prospect of industrial application are extremely important. It can effectively reduce the size of the system, improve detection accuracy, anti-interference ability and wireless communication transmission rate, etc. Avalanche collision transit time (IMPact Avalanche Transit Time referred to as IMPATT) diodes have application value in the fields of millimeter wave / terahertz nondestructive testing, speed and ranging, radar imaging, wireless communication and other fields due to their high operating frequency and high output power. [0003] In the millimeter wave frequency band, the IMPATT diode adopts a mesa structure, which can effe...

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Problems solved by technology

[0003] In the millimeter wave frequency band, the IMPATT diode adopts a mesa structure, which can effectively reduce the parasitic capacitance and inductance effect introduced by the device, and is conducive to improving the operating frequency and output power of the device. With the continuous improvement of the operating frequency of the device (above 100 GHz), The skin effect caused by high frequency is obvious, and the working current of the device is limited to flow within the surface depth δ of the mesa core, which will inevitably increase the effective resistance of the mesa core, and generate a voltage drop along the radial direction of the IMPATT diode vertical to the mesa, which will be Causes the current to form a non-uniform distribution on the mesa IMPATT diode structure and produces an effective series resistance, thereby reducing the efficiency of the device's DC power conversion into RF power

In addition, the skin effect also causes the device to produce a tunnel current effect at high frequencies, destroying the voltage-current phase relationship at the device terminal, making it difficult to provide a 180° avalanche phase delay and reduce the negative resistance of the device

The above factors will lead to a reduction in the output power of the IMPATT diode device under high-frequency operating conditions, poor reliability, and the device is extremely easy to burn out, etc.

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