Wet chemical etching method for preparing large-area and flexible ultra-thin monocrystalline silicon wafers

Abstract

The invention discloses a wet chemical etching method for preparing large-area and flexible ultra-thin monocrystalline silicon wafers, and belongs to the field of semiconductor technology. According to the method, acetone, anhydrous ethanol, deionized water and hydrofluoric acid are adopted to treat a N(100) double-side-polished monocrystalline silicon wafer in advance, so that the surface of the silicon surface is cleaned. Potassium hydroxide, isopropanol and deionized water are uniformly mixed to prepare a reducer and the reducer is preheated in a water-bath. After that, the silicon wafer is well fixed and dipped in the reducer by a clamp. In this way, an ultra-thin wafer of a desired thickness can be obtained through controlling the reaction time and the reaction temperature, The surface of the silicon wafer is bright, flat, smooth and free of any obvious thinning defect, and appears the mirror-surface result. According to the technical scheme of the invention, the thinning process of silicon wafers is simplified by adopting the single-step method, and the characteristics of the wet etching technique in the low-temperature and normal-pressure condition are maintained. Silicon wafers with the thickness thereof smaller than 10 mm are obtained for the first time. Meanwhile, the application range of the wet silicon etching technique is expanded. Therefore, the method provides a novel idea and a novel technical means for the thinning process of silicon wafers.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, and in particular relates to a method for preparing an ultra-thin single-crystal silicon chip used in the preparation of portable, ultra-thin, and fast heat dissipation semiconductor devices. In particular, it relates to a wet chemical etching method for preparing large-area flexible ultra-thin single-crystal silicon wafers. Background technique [0002] Silicon wafer thinning technology can achieve high production efficiency and simple thickness control, and was first applied to the treatment of silicon wafer cutting defects caused by inner circle slicing. With the rapid development of integrated circuit packaging technology, the miniaturization, portability and intelligence of electronic terminal equipment put forward higher requirements for the improvement of chip packaging structure and heat dissipation efficiency. The main building block for device stacking / 3D packaging. Nowadays, s...

AI Technical Summary

Problems solved by technology

When the thickness is less than 50mm, it shows strong brittleness and instability, and is easily broken and damaged during traditional processing and transfer.

In addition to failing to meet the thinning requirements, the traditional thinning process is cumbersome and requires high equipment. The dust discharged from grinding cannot be recovered and pollutes the environment; it also requires high temperature conditions and consumes too much energy.

Therefore, the traditional mechanical thinning process has very large limitations

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