Etching a substrate: processes – Forming or treating mask used for its nonetching function
Patent
1999-04-30
2000-12-05
Bueker, Richard
Etching a substrate: processes
Forming or treating mask used for its nonetching function
216 17, 216 41, 438701, B44C 122, H01L 2131, C03C 2568, C23F 108, C25F 300
Patent
active
061562173
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
BACKGROUND
The present invention relates to a method for the purpose of producing a stencil mask, namely an arrangement which comprises inter alia a planar sheet having a plurality of openings.
SUMMARY OF THE INVENTION
It is particularly difficult to produce stencil masks if they are to be produced over a large area with a small thickness, e.g with a diameter larger than 5 cm and a thickness in the range of 0.25 to 50 .mu.m and furthermore if they have an orifice structure comprising extremely small dimensions in the .mu.m or sub-.mu.m range. Masks of this type are used in the case of a plurality of processes, e.g lithographic applications, for ion-implantation, ion beam etching, vapour-depositing, and as grid lenses or the like.
Known production methods generally comprise thin-etching of thick substrates, e.g of silicon wafers. The orifice structure of the mask can be produced, either prior to or after thin-etching the substrate, by means of a lithographic process. In the first case (mask structure is produced prior to the thin-etching procedure), it is necessary during the thin-etching procedure to protect the orifice structure from being etched, e.g by filling with a specific material which subsequently must be completely removed again. A method of this type is taught in U.S. Pat. No. 4,013,502. EP 0 019 779 also discloses a similar approach. In the second case (orifice structure is produced after the thin-etching procedure), all of the process steps required for the structuring must be performed on the thin sheet, so that said thin sheet can be easily impaired or damaged.
In EP 0 542 519 A from line 28 of column 8 there is described a method for the purpose of producing a mask structure, wherein the rear side of the wafer is etched away up to the thickness of the membrane and then the design of the mask is produced in a lithographic manner on the upper side of the membrane.
The etch-stop of the membrane is achieved by doping a layer, wherein the doping must be highly concentrated such that thereby an extremely high degree of stress is produced in the membrane. A coating in the form of a multilayer dielectric coating is used in order to compensate for this stress.
A disadvantage of this known production method thus resides inter alia in the fact that both the protection of the orifices and the subsequent further treatment of a sheet or membrane are extremely time consuming and therefore expensive.
Therefore, it is the object of the present invention to provide a new method for the purpose of producing stencil masks whilst avoiding the aforementioned disadvantages, which method can be implemented in a convenient and cost-effective manner and minimizes the changes in the mechanical stress characteristics during production. In particular, already known and readily attainable manufacturing technologies can be used, e.g technologies which have been developed for the production of semi-conductors.
In accordance with the invention, these objects are achieved in the case of a method which comprises the following sequence of steps: material comprising a thickness greater than 50 .mu.m, side of the substrate, with the structures for the mask which is to be produced, structures provided for the mask orifices, until the substrate comprises in this region a predetermined membrane thickness less than 50 .mu.m, layer as a masking layer, in order to form in this membrane the orifices for the stencil mask which orifices correspond to the structures of the intermediate layer, and
By virtue of this sequence of steps, the method steps, which are required for the structuring and which cause mechanical loadings, are undertaken prior to the thin-etching procedure, whereas the etching of the mask orifices is not actually performed until after the thin-etching procedure, in order to prevent these orifices from becoming contaminated or impaired during the thin-etching procedure.
Advantageous embodiments of the method in accordance with the invention are evident in the dependent subordinate claims.
REFERENCES:
patent: 4013502 (1977-03-01), Staples
patent: 4919749 (1990-04-01), Mauger et al.
patent: 4966663 (1990-10-01), Mauger
Hammel Ernst
Loschner Hans
Rangelow Ivaylo W.
Bueker Richard
IMS-Ionen Mikrofabrikations Systeme GmbH
Powell Alva C
LandOfFree
Method for the purpose of producing a stencil mask does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for the purpose of producing a stencil mask, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for the purpose of producing a stencil mask will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-958339