Form the method for silicon oxynitride
Technical field
The present invention relates to a kind of method of making semiconductive thin film, particularly a kind of formation has the silicon oxynitride of stabilizing films characteristic as insulation anti-reflecting layer (dielectric antireflectivecoating, method DARC).
Background technology
Semiconductor subassembly utilizes the high density integrated circuit technology to have sizable progress.Utilize the exploitation of stepper, high resolution lithography (lithography) equipment and etching technique, make semiconductor more quicken evolution.Usually, the step of making integrated circuit includes hundreds of roads production process, therefore complicate fabrication process not only, and how effectively group to appoint the workload of the used board of manufacture craft and job specification also be the work of a complexity with the utilization of promoting resource.In manufacture process, the manufacturing bottleneck often occurs at any time and has influence on product quality or qualification rate in many manufacturing technology steps.Because the evolution of technology, photoetching (lithography) resolution is even more important, and rete utilizes photoresist and developing technique to come pattern-making usually.Photoresist is a light-sensitive material, and visible light or UV directly see through photomask (photo mask) and be radiated on the photoresist, to produce pattern (pattern).To have the very semiconductor subassembly of fine pattern in order building, therefore to need a kind of time photoetching making technology of micron resolution capabilities that possesses.And in any optical projection system, comprising the optical semiconductor lithography, the main key of resolution limiting is the numerical aperture (NA) of used lens in this optical system.For a specific wavelength, bigger NA provides preferable resolution.Yet, in order to obtain this advantage, pay great cost also, promptly when NA increased, depth of focus is reduction significantly.And photomask is played the part of epochmaking role in the optical lithography system.And anti-reflecting layer ARC (antireflectivecoating) as organic anti-reflecting layer, is coated on the top usually and promotes resolution to reduce the light reflection.More common optical source wavelength has so-called g line and i line, and wavelength is respectively the ultraviolet ray of 4360 dusts and 3650 dusts.For the manufacture craft of littler live width, must use KrF wavelength that laser is sent out is that the deep UV of 2480 dusts is exposure light source.In fact, use the shorter light source of wavelength, then must the new photoresist material fit of exploitation.
But,, and cause the optical characteristics instability of silicon oxynitride no matter find that with present manufacture craft reflection coefficient with the silicon oxynitride DARC that processing procedure was deposited now is that n or k value all can be drifted about behind precipitation number hour.Present manufacture craft can comprise following step approximately:
Step 1. feeds SiH
4170sccm, N
2O 370seem and He 3800sccm;
Step 2. continues to feed SiH
4170sccm, N
2O 370sccm and He 3800sccm;
Step 3. is carried out thin film deposition, continues to feed SiH
4170seem, N
2O 370sccm and He 3800seem;
Step 4. is opened N
2O plasma (plasma) feeds N
2O 2000sccm and He 2000sccm;
Step 5. is discharged gas, SiH
4-2sccm, N
2O-1sccm and He-1sccm.
See also the experimental data of Fig. 1 and Fig. 2, it shows the silicon oxynitride of prior art deposition respectively, and its n or k value produce drift, and present wild effect.Therefore at present be badly in need of a kind of method that can reclaiming utilization control sheet (reclaim control/dummy wafer).
Summary of the invention
The silicon oxynitride that main purpose of the present invention is to provide a kind of formation to have the stabilizing films characteristic is as insulation anti-reflecting layer (dielectric antireflective coating, method DARC).
The present invention discloses the method for silicon oxynitride DARC (dielectricantireflective coating) film that a kind of formation has the stabilizing films characteristic, it is characterized in that comprising the following step:
Step 1. feeds N
2O and feeding He;
Step 2. feeds SiH
4, N
2O and He;
Step 3. is carried out thin film deposition, continues to feed SiH
4, N
2O and He;
Step 4. is with SiH
4Gas is discharged;
Step 5. feeds N
2O and feeding He;
Step 6. is opened N
2O plasma (plasma) feeds N
2O and He;
Step 7. is with N
2O and He gas are discharged.
The N of above-mentioned steps 1 wherein
2O is that 370sccm feeds with the flow; He is that 3800sccm feeds with the flow.
The N of above-mentioned steps 2 wherein
2O is that 370sccm feeds with the flow: He is that 3800sccm feeds with the flow; SiH
4With the flow is that 370sccm feeds.
The N of above-mentioned steps 3 wherein
2O is that 370sccm feeds with the flow; He is that 3800sccm feeds with the flow; SiH
4With the flow is that 370sccm feeds.
The SiH of above-mentioned steps 4 wherein
4Flow is-the 2sccm discharge.
The N of above-mentioned steps 5 wherein
2O is that 2000sccm feeds with the flow; He is that 2000sccm feeds with the flow.
The N of above-mentioned steps 6 wherein
2O is that 2000sccm feeds with the flow; He is that 2000sccm feeds with the flow.
The N of above-mentioned steps 7 wherein
2O with flow is-the 1sccm discharge; He with flow is-the 1sccm discharge.
Description of drawings
Fig. 1 is the n value experimental data figure of the present invention and prior art.
Fig. 2 is the k value experimental data figure of the present invention and prior art.
Embodiment
All can be no matter the reflection coefficient of the silicon oxynitride DARC that is deposited with the prior art manufacture process is n or k value in drift behind the precipitation number hour, and cause the optical characteristics instability of silicon oxynitride.Therefore, the present invention is in order to improve the shortcoming of above-mentioned technology, and proposes a kind of brand-new manufacture craft, is beneficial to form silicon oxynitride DARC (dielectric antireflectivecoating) film with stabilizing films characteristic.
Manufacturing step of the present invention can comprise following step approximately:
Step 1. is that 370sccm feeds N with the flow
2O and flow are that 3800sccm feeds He;
Step 2. feeds SiH
4170sccm, N
2O 370sccm and He 3800sccm;
Step 3. is carried out thin film deposition, continues to feed SiH4, and flow is 170sccm, N
2O 370sccm and He 3800sccm;
Step 4. is with SiH
4Gas is discharged, and flow is-2sccm;
Step 5. feeds N with flow 2000sccm
2O and 2000sccm feed He;
Step 6. is opened N
2O plasma (plasma) feeds N so that energy of plasma acceleration vapour deposition to be provided
2O 2000sccm and He 2000sccm;
Step 7. is discharged gas, N
2The O flow is-1sccm and He flow be-1sccm.
See also the experimental data of Fig. 1 and Fig. 2, it shows that respectively the silicon oxynitride that is deposited with the present invention has stable n or k value, does not produce drift phenomenon.Therefore, can improve the shortcoming of prior art significantly.
The present invention with preferred embodiment explanation as above and is familiar with this field skill person, in not breaking away from spiritual scope of the present invention, retouch when doing a little change certainly, but it still belongs within the scope of the invention.