Intermittent plasma oxidation method and device and preparation method of solar cell

Abstract

The embodiment of the invention provides an intermittent plasma oxidation method, a preparation method of a TOPCon solar cell, an intermittent plasma oxidation device and a computer readable storage medium. The intermittent plasma oxidation method comprises the steps: enabling processing gas plasma in a plasma processing chamber to be ionized through an excitation signal, so that to-be-processed gas in the processing chamber is oxidized to form an oxide layer, wherein the excitation signal comprises an on state and an off state which are alternately carried out, a pulse or sinusoidal signal is output during the on state, and no power is output during the off state; and the duration of the on state and the off state is longer than a pulse or sinusoidal signal period.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to an intermittent plasma oxidation method, a TOPCon solar cell preparation method, a plasma oxidation device and a computer-readable storage medium. Background technique [0002] TOPCon (Tunnel Oxide Passivated Contact) solar cells have attracted widespread attention in the photovoltaic industry in recent years. A typical TOPCon solar cell such as figure 1 As shown, it includes a substrate 11, an emitter 12 formed on the front surface of the substrate 11, a passivation anti-reflection layer 13 and a first electrode 14 formed on the emitter 12, and a An ultrathin oxide layer 15 , a heavily doped polysilicon layer 16 formed on the ultrathin oxide layer 15 , and a second electrode 17 formed on the heavily doped polysilicon layer 16 . Wherein, the substrate 11 may be, for example, a silicon substrate, and the ultra-thin oxide layer 15 may be, for example, a silico...

AI Technical Summary

Problems solved by technology

The thermal oxidation method usually adopts a temperature of 600-650°C. At this temperature, a graphite boat cannot be used but a quartz boat is required. In this way, the preparation of the silicon oxide layer and the polysilicon layer needs to be completed in two separate reaction chambers during the production process. After the thermal oxidation is completed, the substrate needs to be taken out of the quartz boat and put into the graphite boat for the preparation of the polysilicon layer, which not only adds additional production steps, but also introduces uncertain factors that affect the yield, such as substrate pick-and-place Damage to the silicon oxide layer during the process

For the PECVD method, the inventors of the present invention have found that the silicon oxide layer prepared by the existing PECVD method has the problem of low uniformity, and its uniformity has not yet reached the requirements for mass production of high-efficiency TOPCon solar cells.

Due to the characteristics of atomic layer deposition, the PEALD method can obtain a relatively uniform silicon oxide layer with a large area, but the PEALD method needs to utilize gases such as organosilanes as precursors, which significantly increases the production cost of TOPCon solar cells. In addition, the invention of the present invention People also found that in the oxidation process of the PEALD method, the oxygen-containing plasma not only oxidizes the organic silane adsorbed on the surface, but also oxidizes the substrate under the adsorption layer, thereby affecting the quality of passivation.

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