A preparation method of indium column, infrared focal plane array detector

Abstract

The invention discloses an indium column and a preparation method thereof. The preparation method comprises: A. coating a photoresist layer (20) on a chip (10); B. forming a deposition on the photoresist layer (20) Hole (21); C, deposit metal and indium successively, form bottom metal layer (30) and indium layer (41) successively on photoresist layer (20), and form bottom metal layer successively in deposition hole (21) (30) and indium pillars (42); D, removing the photoresist layer (20) and the underlying metal layer (30) and indium layer (41) on it. The preparation method can shorten the process time for preparing the indium column and improve work efficiency; at the same time, it can also avoid the breakage of fragile samples such as gallium arsenide in the device, and improve the yield of the indium column. The invention also discloses the application of the indium column prepared according to the preparation method in an infrared focal plane array detector. The indium column can avoid problems such as short circuit of a pixel caused by a wet stripping process, and improve device performance.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, and in particular relates to a preparation method of an indium column, and also relates to an application of the indium column in an infrared focal plane array detector. Background technique [0002] Infrared focal plane array is the core component of modern infrared imaging system, and its manufacturing process includes the preparation of infrared focal plane devices, the preparation of readout circuits, and the flip-chip interconnection of devices and circuits. Flip-chip interconnection generally adopts the flip-chip interconnection of indium pillars. To maximize the success rate of interconnection, it is particularly important to prepare high-quality indium pillars. At present, the commonly used preparation method of indium column is thermal evaporation indium column combined with wet stripping process, that is, the photoresist mask is dissolved by organic solvent or glue remover, so th...

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Problems solved by technology

At present, the commonly used preparation method of indium column is thermal evaporation indium column combined with wet stripping process, that is, the photoresist mask is dissolved by organic solvent or glue remover, so that the indium film on the mask falls off, but indium is a very " "sticky" metals, the photoresist is easily dissolved, but the indium film sticks back to the chip. Once the metal indium sticks back to the chip, it is difficult to peel it off, which will cause many pixel short circuits and seriously affect device performance; and the wet stripping process generally needs to be soaked in a solvent for a certain period of time, generally more than 1 hour, and then the solvent is heated or ultrasonically vibrated to make the indium film crack and fall off. This method not only takes a long time, but also Moreover, brittle materials such as gallium arsenide in the device are prone to fatal damage such as cracking, which affects the yield

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