High-quality silicon nitride medium passivation layer treatment process based on supercritical fluid

Abstract

The invention discloses a high-quality silicon nitride medium passivation layer treatment process based on supercritical fluid. The high-quality silicon nitride medium passivation layer treatment process comprises the following steps: vertically placing a substrate sample with a Si3N4 medium passivation layer into a reaction container; filling deionized water into the reaction container and sealing; controlling the pressure intensity, and filling CO2 or N2O supercritical gas into the reaction container; heating and pressurizing the reaction container, and maintaining the pressure to enable the interior of the reaction container to be in a supercritical state; keeping supercritical state treatment, performing pressure reduction treatment on the reaction container, and keeping the supercritical treatment condition of 20-22MPa; and after the reaction is finished, cooling the reaction container, and taking out the reaction container when the pressure is reduced to atmospheric pressure. According to the method, the trap and the interface state in the Si3N4 dielectric layer are passivated at low temperature and high pressure, the operation is simple and convenient, and the problems caused by the high-temperature annealing process are avoided, so that the quality of the Si3N4 dielectric layer is improved, the breakdown electric field is improved, and the leakage current density is reduced.

Description

technical field [0001] The invention belongs to semiconductor Si 3 N 4 The technical field of passivation layer materials, in particular to a high-quality Si based on supercritical fluid 3 N 4 Dielectric passivation layer processing technology and its application. Background technique [0002] In order to obtain high-quality Si 3 N 4 Dielectric passivation layer to improve the reliability and stability of the device, researchers have made a variety of different attempts. At present, heat treatment after depositing a silicon nitride film is a method mainly used to improve the performance of silicon nitride. [0003] For example, Reynes et al. heat-treated silicon nitride films with low H content at 1200K, and the results showed that the stability of the increased H content deteriorated; Z Lu et al. deposited by remote plasma enhanced chemical vapor deposition (RPECVD) method The silicon nitride film was subjected to rapid heat treatment at 400°C to 900°C, and the chang...

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Problems solved by technology

However, the silicon nitride film also has its shortcomings, the most prominent point is that the interface state density between the silicon nitride film and the active layer (single crystal silicon or polycrystalline silicon) is relatively high, and the silicon nitride passivation layer has shocks. Low cross-field strength and high leakage current, film quality has become the main factor limiting silicon nitride

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