Equipment for preparing gate dielectric layer

Abstract

The invention provides equipment for preparing a gate dielectric layer. The equipment comprises a thermal treatment process cavity used for growing a SiO2 gate dielectric layer, a plasma nitriding process cavity used for performing plasma nitrogen injection on the gate dielectric layer to form a Si-N bond, a high-temperature nitriding cavity used for repairing lattice damage in the gate dielectric layer and stabilizing the Si-N bond, a low-temperature oxidizing cavity used for repairing a gate dielectric layer/channel interface, a control unit used for controlling conversion of a semiconductor substrate among all the process cavities and opening/closing of all the process cavities, and a conveying device used for conveying the semiconductor substrate among all the process cavities. By adopting a process for preparing the gate dielectric layer in the equipment provided by the invention, the Si-N bond tends to be stable to prevent the volatilization of N atoms, the N concentration in a SiON gate dielectric is stabilized, the dielectric constant of the SiON gate dielectric is increased, reduction of a carrier mobility caused by interface defect is avoided, and the interface quality and the performance of a device are improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a device for preparing a gate dielectric layer. Background technique [0002] The rapid development of Very Large Scale Integration (VLSI) and Ultra Large Scale Integration (ULSI) has put forward more special requirements for device processing technology. Among them, the requirement for gate oxide layer when the feature size of MOS devices enters the nanometer era is an obvious challenge. The preparation process of the gate dielectric layer is a key technology in the semiconductor manufacturing process, which directly affects and determines the electrical characteristics and reliability of the device. [0003] The key performance indicator of MOSFET devices is the drive current, and the magnitude of the drive current depends on the gate capacitance. The gate capacitance is proportional to the surface area of ​​the gate and inversely proportional to the thickn...

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Problems solved by technology

[0018] In the above preparation process, since the concentration of nitrogen atoms doped in the gate dielectric layer is high and mainly distributed on the upper surface of the gate dielectric layer, the temperature, gas atmosphere and time interval of the subsequent PNA process must be strictly controlled to prevent the gate dielectric The influence of the intrinsic oxide layer and organic adsorption in the layer on nitrogen doping; in addition, the high-temperature annealing process of PNA (Post Nitridation Anneal) can easily cause the volatilization of nitrogen atoms on the surface, and cause the nitrogen atoms to gain energy and continue to diffuse. cause some nitrogen atoms to accumulate in SiO 2 / Si interface, thus negatively affecting the mobility of carriers in the channel

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