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CN-121985748-A - Method for forming semiconductor device

CN121985748ACN 121985748 ACN121985748 ACN 121985748ACN-121985748-A

Abstract

The invention provides a method for forming a semiconductor device, which comprises the steps of firstly obtaining the interface state forbidden bandwidth between a semiconductor substrate and a gate dielectric layer, then presetting the wavelength of incident light according to the interface state forbidden bandwidth, and carrying out ultraviolet irradiation treatment on the MOS device according to the preset wavelength of the incident light so that the incident light penetrates through a metal grid and the gate dielectric layer to adjust the threshold voltage of the MOS device. By carrying out ultraviolet irradiation treatment on the MOS device, interface state defects between the semiconductor substrate and the gate dielectric layer and defect state traps in the gate dielectric layer can be excited, so that photoelectric effect is induced, electron hole pairs are generated, holes are easily captured by the interface state traps and the defect state traps, positive charges can be formed, local electric field distribution is changed, and threshold voltage of the MOS device is adjusted.

Inventors

  • YE BO

Assignees

  • 重庆芯联微电子有限公司

Dates

Publication Date
20260505
Application Date
20251226

Claims (10)

  1. 1. A method of forming a semiconductor device, comprising: Providing a semiconductor substrate, wherein an MOS device is formed on the semiconductor substrate, the MOS device comprises a gate dielectric layer and a metal gate, and the metal gate is positioned on the gate dielectric layer; Acquiring an interface state forbidden bandwidth between the semiconductor substrate and the gate dielectric layer; Presetting the wavelength of incident light according to the interface state forbidden bandwidth; And carrying out ultraviolet irradiation treatment on the MOS device according to the preset wavelength of the incident light, so that the incident light penetrates through the metal gate and the gate dielectric layer to adjust the threshold voltage of the MOS device.
  2. 2. The method for forming a semiconductor device according to claim 1, wherein the gate dielectric layer comprises a first gate dielectric layer and a second gate dielectric layer, the second gate dielectric layer covers the first gate dielectric layer, and a material of the second gate dielectric layer is different from a material of the first gate dielectric layer.
  3. 3. The method of forming a semiconductor device of claim 2, wherein the material of the first gate dielectric layer comprises silicon oxide.
  4. 4. The method of forming a semiconductor device of claim 2, wherein the material of the second gate dielectric layer comprises hafnium oxide or titanium oxide.
  5. 5. The method for forming a semiconductor device according to claim 1, wherein when the ultraviolet irradiation treatment is performed, a wavelength of the incident light satisfies the following relation: λ is less than or equal to (h×c)/E 0 , where λ is the wavelength of incident light, E 0 is the interface state forbidden bandwidth between the semiconductor substrate and the gate dielectric layer, h is the planck constant, and c is the light speed.
  6. 6. The method for forming a semiconductor device according to claim 5, wherein a wavelength of the incident light is 355nm or less when the ultraviolet irradiation treatment is performed.
  7. 7. The method according to claim 6, wherein the wavelength of the incident light is 200nm to 218nm when the ultraviolet irradiation treatment is performed.
  8. 8. The method for forming a semiconductor device according to claim 1, wherein when the MOS device is subjected to ultraviolet irradiation treatment, further comprising adjusting power of the ultraviolet irradiation treatment.
  9. 9. The method of forming a semiconductor device according to claim 8, wherein the power of the ultraviolet irradiation treatment is 50w to 100w.
  10. 10. The method of forming a semiconductor device of claim 1, wherein an inter-metal dielectric layer is further formed on the semiconductor substrate, the inter-metal dielectric layer covering the metal gate; when the ultraviolet irradiation treatment is performed, the incident light also penetrates through the inter-metal dielectric layer.

Description

Method for forming semiconductor device Technical Field The present invention relates to the field of integrated circuit technology, and in particular, to a method for forming a semiconductor device. Background In the method for forming a semiconductor device, it is generally necessary to adjust the electrical properties of the semiconductor device, such as adjusting the threshold voltage of the device, and the current adjustment method is to adjust the threshold voltage of the device by adjusting the ion implantation dose in the device. However, in the actual production process, the WAT electrical test of the semiconductor device generally needs to obtain an electrical test result after the device finishes the preparation of the metal layer, and the test structure has a certain hysteresis. Therefore, the device which has undergone the ion implantation process cannot timely compensate the electrical property, the process cost is increased, and the device yield is reduced. Disclosure of Invention The invention aims to provide a method for forming a semiconductor device, which is used for adjusting the threshold voltage of the device. In order to achieve the above object, the present invention provides a method for forming a semiconductor device, comprising: Providing a semiconductor substrate, wherein an MOS device is formed on the semiconductor substrate, the MOS device comprises a gate dielectric layer and a metal gate, and the metal gate is positioned on the gate dielectric layer; Acquiring an interface state forbidden bandwidth between the semiconductor substrate and the gate dielectric layer; Presetting the wavelength of incident light according to the interface state forbidden bandwidth; And carrying out ultraviolet irradiation treatment on the MOS device according to the preset wavelength of the incident light, so that the incident light penetrates through the metal gate and the gate dielectric layer to adjust the threshold voltage of the MOS device. Optionally, in the method for forming a semiconductor device, the gate dielectric layer includes a first gate dielectric layer and a second gate dielectric layer, the second gate dielectric layer covers the first gate dielectric layer, and a material of the second gate dielectric layer is different from a material of the first gate dielectric layer. Optionally, in the method for forming a semiconductor device, a material of the first gate dielectric layer includes silicon oxide. Optionally, in the method for forming a semiconductor device, a material of the second gate dielectric layer includes hafnium oxide or titanium oxide. Optionally, in the method for forming a semiconductor device, when the ultraviolet irradiation treatment is performed, a wavelength of the incident light satisfies the following relationship: λ is less than or equal to (h×c)/E 0, where λ is the wavelength of incident light, E0 is the interface state forbidden bandwidth between the semiconductor substrate and the gate dielectric layer, h is the planck constant, and c is the light speed. Optionally, in the method for forming a semiconductor device, when the ultraviolet irradiation treatment is performed, a wavelength of the incident light is 355nm or less. Optionally, in the method for forming a semiconductor device, when the ultraviolet irradiation treatment is performed, a wavelength of the incident light is 200nm to 218nm. Optionally, in the method for forming a semiconductor device, when the MOS device is subjected to ultraviolet irradiation treatment, adjusting the power of the ultraviolet irradiation treatment is further included. Optionally, in the method for forming a semiconductor device, the power of the ultraviolet irradiation treatment is 500w to 100w. Optionally, in the method for forming a semiconductor device, an inter-metal dielectric layer is further formed on the semiconductor substrate, and the inter-metal dielectric layer covers the metal gate; when the ultraviolet irradiation treatment is performed, the incident light also penetrates through the inter-metal dielectric layer. In the method for forming the semiconductor device, the interface state forbidden bandwidth between the semiconductor substrate and the gate dielectric layer is obtained, then the wavelength of incident light is preset according to the interface state forbidden bandwidth, and ultraviolet irradiation treatment is carried out on the MOS device according to the preset wavelength of the incident light, so that the incident light penetrates through the metal gate and the gate dielectric layer, and the threshold voltage of the MOS device is adjusted. By carrying out ultraviolet irradiation treatment on the MOS device, interface state defects between the semiconductor substrate and the gate dielectric layer and defect state traps in the gate dielectric layer can be excited, so that photoelectric effect is induced, electron hole pairs are generated, holes are easily captured by the interface state tra