Semiconductor device and preparation method thereof

Abstract

The invention provides a semiconductor device and a preparation method thereof, relating to the technical field of semiconductors. The preparation method has the beneficial effects that the threshold voltages of transistors can be effectively regulated by forming germanium-silicon layers in channel regions of the transistors, so that the prepared semiconductor device has different threshold voltages; the semiconductor device can be prepared by adopting the preparation method of the semiconductor device; as the channel regions have different concentrations of germanium-silicon layers, regulation of the threshold voltages of the transistors can be effectively achieved, and then the semiconductor device has good threshold voltage characteristics.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a semiconductor device and a manufacturing method thereof. Background technique [0002] In the field of semiconductor technology, how to reduce power consumption while ensuring the performance of semiconductor devices has become a major challenge faced by people. Power consumption / performance optimization (Power-performance optimization) usually requires semiconductor devices to have multiple threshold voltages (Vt) and low off-current (Ioff). In planar bulk silicon semiconductor devices, multiple threshold voltages are achieved by using two work function layers (corresponding to NFET and PFET respectively) and using different gate lengths and doping concentrations. Fin Field Effect Transistor (FinFET) has excellent electrostatic control ability due to its small device size and small operating voltage. However, the reduction of device size and operating voltage, especial...

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Problems solved by technology

Fin Field Effect Transistor (FinFET) has excellent electrostatic control ability due to its small device size and small operating voltage. However, the reduction of device size and operating voltage, especially the reduction of operating voltage, leads to the threshold Control of voltage variability becomes very difficult

In semiconductor devices with large-scale application of Fin Field Effect Transistors (FinFETs), as the process node continues to decrease, the number of ions that need to be implanted continues to decrease (for example, the number of ions that need to be implanted for devices using a 10nm process node is very small), The ion implantation process becomes very difficult to control

[0003] Different metal capping process (capping) can effectively adjust the threshold voltage of FinFET, but this method requires complex integration process and does not bring other improvements

However, the traditional ion implantation process will reduce the ion mobility of the device and may cause random fluctuations of dopants that have a very bad impact on the device.

Also, for the manufacturing method of semiconductor devices using metal gate technology, the ion implantation process also faces the challenge of controlling the ion implantation dose to prevent ions from penetrating into the high-k dielectric layer or the channel region of the device

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