Method for forming polysilicon gate and semiconductor device comprising polysilicon gate

Abstract

The invention discloses a method for forming a polysilicon gate and a semiconductor device comprising the polysilicon gate. The method comprises the following steps of dividing a substrate into a high-voltage device region and a low-voltage device region by forming a device insulation region in the substrate, forming a groove in the high-voltage device region, forming a gate oxide layer on the substrate, depositing a polycrystalline silicon layer on the gate oxide layer, and etching to remove at least one part of the polycrystalline silicon layer, so that the thickness of the part, corresponding to the low-voltage device region, of the polycrystalline silicon layer is different from the thickness of the part, corresponding to the high-voltage device region, of the polycrystalline silicon layer.

Description

technical field [0001] The invention relates to a semiconductor manufacturing process, in particular to a method for forming a polysilicon gate and a semiconductor device including the polysilicon gate. Background technique [0002] In the current process, because high-voltage devices in semiconductor devices need to withstand higher voltages than low-voltage devices, the reliability of some corresponding performance (such as the performance of hot carrier injection) will also be reduced. In order to solve this problem, Greater energy is required for ion implantation in the high-voltage device region. In order to prevent the high-voltage device from being penetrated by ions and cause device failure, the polysilicon thickness required for the high-voltage device region in the semiconductor device will also be thicker. [0003] The existing technology mainly solves this problem by adding a layer of hard mask on the polysilicon gate. Since the hard mask layer needs to be remove...

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Problems solved by technology

[0002] In the current process, because high-voltage devices in semiconductor devices need to withstand higher voltages than low-voltage devices, the reliability of some corresponding performance (such as the performance of hot carrier injection) will also be reduced. In order to solve this problem, More energy is required for ion implantation in the high-voltage device area. In order to prevent the high-voltage device from being penetrated by ions and cause device failure, the thickness of polysilicon required for the high-voltage device area in the semiconductor device will also be thicker.

[0003] The existing technology mainly solves this problem by adding a layer of hard mask on the polysilicon gate. Since the hard mask layer needs to be removed in the subsequent process, the removal process will not only increase the cost but also cause damage to the device. damage, thereby affecting the performance of the device

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