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CN-122010045-A - Dielectric-vanadium oxide laminated structure and dry etching method and application thereof

CN122010045ACN 122010045 ACN122010045 ACN 122010045ACN-122010045-A

Abstract

The invention belongs to the technical field of semiconductor manufacturing, and particularly relates to a dielectric-vanadium oxide laminated structure, a dry etching method and application thereof. The etching method comprises the steps of preparing a substrate, loading a laminated substrate with a photoresist mask into a cavity of plasma etching equipment, stabilizing the cavity, setting radio frequency power, bias power, cavity pressure, gas flow, substrate temperature and cavity temperature, starting etching after the cavity parameters are stabilized, starting the plasma etching equipment to continuously etch a dielectric protection layer and a vanadium oxide layer of the laminated substrate, detecting an end point, monitoring an etching end point in real time, and closing the plasma etching equipment when detecting a vanadium oxide layer etching completion signal to remove static electricity of the laminated substrate to finish etching. The etching method can utilize a single gas formula in the same reaction environment to realize continuous, uniform and shape-controllable single-step dry etching on the dielectric-vanadium oxide laminated structure.

Inventors

  • CAO DI
  • Du Sichang
  • MA BINBIN
  • WANG ZHAOFENG
  • WANG SHIKUAN

Assignees

  • 无锡尚积半导体科技股份有限公司

Dates

Publication Date
20260512
Application Date
20260401

Claims (10)

  1. 1. The dry etching method of the dielectric-vanadium oxide laminated structure is characterized by comprising the following steps of: step S1, preparing a substrate, namely loading a laminated structure substrate with a photoresist mask into a chamber of plasma etching equipment; Step S2, stabilizing a chamber, namely introducing mixed gas of first gas containing fluorine, second gas containing chlorine and inert gas serving as third gas as etching gas, setting radio frequency power, bias power, chamber pressure, gas flow, substrate temperature and chamber temperature, and starting etching after the parameters of the chamber are stabilized; Step S3, single-step main etching, namely starting plasma etching equipment and continuously etching the dielectric protection layer and the vanadium oxide layer of the laminated structure substrate; And S4, detecting an end point, namely monitoring an etching end point in real time, and closing the plasma etching equipment when detecting a metal oxide layer etching completion signal to remove static electricity of the laminated structure substrate to finish etching.
  2. 2. The dry etching method of the dielectric-vanadium oxide laminated structure according to claim 1, wherein the laminated structure substrate sequentially comprises a stacked metal oxide layer and a dielectric protection layer from bottom to top, the metal oxide layer is vanadium oxide or other metal oxides except vanadium oxide, the thickness of the metal oxide layer is 80-120nm, the dielectric protection layer comprises a SiO 2 layer and/or a SiNx layer, and the total thickness of the dielectric protection layer is 30-50nm.
  3. 3. The method according to claim 1, wherein in step S2, the first gas includes one or more of CF 4 、CHF 3 and SF 6 , and the second gas includes one or both of Cl 2 and BCl 3 .
  4. 4. A dry etching method of a dielectric-vanadium oxide laminated structure according to claim 1 or 3, wherein the volume flow ratio of the first gas to the second gas is 1:10-1:0.3, and the flow rate of the third gas is 10-100sccm.
  5. 5. The dry etching method of a dielectric-vanadium oxide laminated structure according to claim 1, wherein the plasma etching apparatus is an inductively coupled plasma etching apparatus, the radio frequency power is 300-600W, the bias power is 50-300W, and the chamber pressure is 5-20 mTorr.
  6. 6. The method of claim 1-5, wherein the first gas is CF 4 , the second gas is Cl 2 , the volume flow ratio of the first gas to the second gas is 1:10-1:1, the flow of the third gas is 10-100sccm, the rf power of the plasma etching apparatus is 300-600W, the bias power is 50-300W, and the chamber pressure is 5-20 mTorr.
  7. 7. The dry etching method of a dielectric-vanadium oxide laminated structure according to any one of claims 1 to 5, wherein the first gas is SF 6 , the second gas is BCl 3 , the volume flow ratio of the first gas to the second gas is 1:10-1:0.3, the flow of the third gas is 10-100sccm, the rf power of the plasma etching apparatus is 200-500W, the bias power is 50-200W, and the chamber pressure is 5-15 mTorr.
  8. 8. The method according to claim 1, wherein in step S4, the etching endpoint is detected in real time by an optical emission spectrum or a laser interferometer.
  9. 9. A dielectric-vanadium oxide stack structure, characterized in that it is etched by the etching method according to any one of claims 1-8.
  10. 10. Use of a medium-vanadium oxide stack according to claim 9 for the patterned preparation of a thermal-sensitive unit and an adiabatic bridge leg in an uncooled infrared focal plane array detector.

Description

Dielectric-vanadium oxide laminated structure and dry etching method and application thereof Technical Field The invention belongs to the technical field of semiconductor manufacturing, and particularly relates to a dielectric-vanadium oxide laminated structure, a dry etching method and application thereof. Background With the continuous development of infrared detectors (such as uncooled infrared focal plane arrays, IRFPA) and intelligent light control devices, laminated film structures composed of metal oxides including vanadium oxide and dielectric materials (such as SiO 2, siNx) are increasingly used in related devices. Vanadium oxide materials are widely used in heat sensitive units of uncooled infrared detectors due to their excellent Temperature Coefficient of Resistance (TCR), while dielectric materials SiNx are commonly used as structural support layers and insulating protective layers of insulating bridge legs, which together form a multilayer stack system of device cores. In the patterning process of the laminated structure, the conventional process generally adopts a step-by-step etching scheme, namely firstly etching the dielectric layer SiNx by using fluorine-containing gas (such as CF 4 or SF 6), switching the gas formula after the patterning process is completed, and then etching the lower vanadium oxide by using chlorine-containing gas. The method has the advantages of complex flow, easy introduction of pollution at a heterogeneous interface, and mismatching of etching rates between different film layers, thereby leading to poor morphology. The two-step etching route has the following technical defects: the process steps are complicated, each step of switching needs to be carried out in a gas stabilization stage, so that the process time redundancy is caused, and the overall takt time is obviously increased. Residual gas and side reaction products are easily introduced into a SiNx-vanadium oxide heterogeneous interface in the gas switching transition period, so that interface pollution is caused, and the performance of a device is influenced. The etching rates of different materials in the two-step etching are independently optimized, so that the morphology cooperative control at the lamination interface is difficult to realize, the profile of the side wall is discontinuous, the etching angle is inconsistent, and the compatibility of the subsequent process is affected. Disclosure of Invention The invention aims to overcome the defects in the prior art and provides a dielectric-vanadium oxide laminated structure and a dry etching method and application thereof. According to the invention, a fluorine/chlorine (F/Cl) composite gas system is introduced, and the characteristics of high chemical etching activity of fluorine free radicals (F) on the dielectric layer SiNx and the characteristic of the reaction of chlorine free radicals (Cl) with metal elements (V, O and the like) to generate volatile halides are utilized, so that continuous etching of two materials of SiNx and vanadium oxide is realized in the same process step through the synergistic effect of physical bombardment and chemical reaction of plasmas, intermediate gas switching is not needed, and continuous and equal-speed single-step etching of two materials with different properties is realized in the same reaction environment. The dry etching method can realize continuous, uniform and shape-controllable single-step dry etching on the dielectric-vanadium oxide laminated structure by utilizing a single gas formula in the same reaction environment. In order to achieve the technical purpose, the technical scheme adopted by the embodiment of the invention is as follows: in a first aspect, an embodiment of the present invention provides a dry etching method for a dielectric-vanadium oxide stacked structure, including the following steps: step S1, preparing a substrate, namely loading a laminated structure substrate with a photoresist mask into a chamber of plasma etching equipment; Step S2, stabilizing a chamber, namely introducing mixed gas of first gas containing fluorine, second gas containing chlorine and inert gas serving as third gas as etching gas, setting radio frequency power, bias power, chamber pressure, gas flow, substrate temperature and chamber temperature, and starting etching after the parameters of the chamber are stabilized; Step S3, single-step main etching, namely starting plasma etching equipment and continuously etching the dielectric protection layer and the vanadium oxide layer of the laminated structure substrate; And S4, detecting an end point, namely monitoring an etching end point in real time, and closing the plasma etching equipment when detecting a metal oxide layer etching completion signal to remove static electricity of the laminated structure substrate to finish etching. Further, the laminated structure substrate sequentially comprises a stacked metal oxide layer and a dielectric protective layer from b