EP0413040A1
Expired / Lapsed
EP
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Method of producing ultrafine silicon tips for the AFM/STM profilometry
Assignee: International Business Machines Corp
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Filing: 1989-08-16
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Granted: —
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Expires: 2009-08-16
Abstract
Abstract A method is described for producing ultrafine silicon tips for the AFM/STM profilometry comprising: 1. providing a silicon substrate and applying a silicon dioxide layer thereto; 2. producing a mask in said silicon dioxide layer by photolithography and wet or dry etching; 3. producing a tip shaft by transferring the mask pattern, produced in step 2, by reactive ion etching into the silicon substrate; 4. thinning the shaft and forming a base by isotropic wet etching; and 5. removing the mask by etching. The resulting tip shaft with a rectangular end may be pointed by argon ion milling. In a second embodiment there is an anisotropic wet etching step, prior to step 5, through the intact silicon dioxide mask, producing a negative profile of the shaft immediately below the mask. After this etching step the mask is removed by etching.
Inventors
- 👤 Thomas Bayer
- 👤 Johann Dr. Dipl.-Phys. Greschner
- 👤 Helga Weiss
- 👤 Olaf Dr. Dipl.-Phys. Wolter
- 👤 Hemantha K. Dr. Dipl.-Phys. Wickramasinghe
- 👤 Yves Dr. Dipl.-Phys. Martin
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 09:39
CPC Classifications
G; G01; G01Q; G01Q60/00; G01Q60/24; G01Q60/38; G01Q60/02; G01Q60/04; G01Q60/10; G01Q60/16; G01Q70/00; G01Q70/08; G01Q70/10; Y; Y10; Y10S; Y10S977/00; Y10S977/84; Y10S977/849; Y10S977/86; Y10S977/875; Y10S977/878
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
86 words
Method of producing ultrafine silicon tips for the AFM/STM profilometry comprising the following steps: 1. providing a silicon substrate (1) and applying a masking layer (2) thereto; 2. producing a mask pattern in said layer (2) by photolithography and etching; 3. producing the tip shaft (3) by transferring the mask pattern, produced in step 2, by reactive ion etching into the silicon substrate (1); 4. thinning the shaft (3) and forming a base (5) by isotropic wet etching; and 5. removing the mask (2) by etching.
Claim 2
Dependent Claim
86 words
Method of producing ultrafine silicon tips for the AFM/STM profilometry comprising the following steps: 1. providing a silicon substrate (1) and applying a masking layer (2) thereto; 2. producing a mask pattern in said layer (2) by photolithography and etching; 3. producing the tip shaft (3) by transferring the mask pattern, produced in step 2, by reactive ion etching into the silicon substrate (1); 4. thinning the shaft (3) and forming a base (5) by isotropic wet etching; and 5. removing the mask (2) by etching.
Claim 3
Dependent Claim
41 words
Method of claim 1, further comprising: prior to step 5 (claim 1) anisotropic wet etching through the intact mask (2), thereby producing a negative profile (6) of the shaft (3) immediately below said mask (2), and subsequently removing said mask (2).
Claim 4
Dependent Claim
22 words
Method of claim 1, wherein the rectangular shaft end, obtained by the removal of mask (2), is pointed by argon ion milling.
Claim 5
Dependent Claim
24 words
Method of claim 1, wherein a silicon dioxide layer (2) is applied to the silicon substrate (1) in a thickness of about 1 µm.
Claim 6
Dependent Claim
33 words
Method of claims 1 and 4, wherein an about 3 µm thick photoresist layer is applied to the silicon dioxide layer (2), and the desired mask pattern is defined in said photoresist layer.
Claim 7
Dependent Claim
43 words
Method of claims 1, 4 and 5, wherein the mask pattern in the photoresist layer is transferred into the silicon dioxide layer (2) by wet etching or reactive ion etching with CF₄ as etch gas, and with a pressure of about 10 µbar.
Claim 8
Dependent Claim
43 words
Method of claims 1, 4 and 6, wherein the silicon dioxide mask pattern (2) is transferred into the silicon substrate (1) to the desired depth by anisotropic reactive ion etching with chlorine/argon as etch gas, and with a pressure of about 20 µbar.
Claim 9
Dependent Claim
30 words
Method of claim 7, wherein by isotropic wet etching the side wall redeposition layer (4) is removed from the shaft (3), and the latter is thinned at the same time.
Claim 10
Dependent Claim
34 words
Method of claims 1 and 2, wherein the negative profile (6) of the shaft (3) immediately below the mask (2) is produced by anisotropic wet etching with aqueous 37.5 wt% KOH at about 60°C.
Claim 11
Dependent Claim
25 words
Method of one or several of claims 1 to 9, wherein the mask (2) is removed by etching with 5 : 1 buffered hydrofluoric acid.
Claim 12
Dependent Claim
52 words
Micromechanical sensor for AFM/STM profilometry comprising a silicon base carrying a tip shaft with an end shaped for interaction with the surface of a sample to be profiled, characterized in that said base and said tip shaft with the shaped end form one integral part micromechanically manufactured from one piece of material.
Claim 13
Dependent Claim
52 words
Micromechanical sensor for AFM/STM profilometry comprising a silicon base carrying a tip shaft with an end shaped for interaction with the surface of a sample to be profiled, characterized in that said base and said tip shaft with the shaped end form one integral part micromechanically manufactured from one piece of material.
References Cited (Backward Citations)
No citation records indexed.
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