EP0178000A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method of forming submicron grooves in, for example, semiconductor material and devices obtained by means of this method
Assignee: Koninklijke Philips NV
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Filing: 1985-09-13
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Granted: —
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Expires: 2005-09-13
Abstract
Abstract On a layer having a stepped relief, such as a masking layer (4) having openings (5) on a substrate region (2) is provided a first layer (6), which, whilst maintaining the stepped relief, is covered by a second masking layer (8) and a convertible layer (9). By conversion of the convertible layer (9) (by means of ion implantation, oxidation, silicidation) this layer becomes selectively etchable. After removal of the non-converted parts, an intermediate mask (8) is formed with an opening in the second masking layer (8) along the edge of a depression (7). By means of the mask (8) thus obtained, grooves (11) are formed by anisotropic etching in the first layer (6) and, as the case may be, in the subjacent substrate region (2). When grooves are formed in a substrate region (2) of semiconductor material, these grooves may be filled with oxide (25) for forming insulated regions, If a first layer (6) of polycrystalline silicon is used on a substrate region (2) of silicon, this layer (6) can serve as a doping source and a connection, respectively. Thus, various kinds of transistors (MOSFET and bipolar transistors) can be manufactured. The second masking layer (8) and the convertible layer (9) may be realized, if required, as a single layer (65).
Inventors
- 👤 Henricus Godefridus Rafael Maas
- 👤 Johannes Arnoldus Appels
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 20:53
CPC Classifications
H; H10; H10P; H10P76/00; H10P76/40; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/10; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/947
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
225 words
A method of forming at least one narrow groove in a substantially uniform layer of a first material, in which the width of the groove is determined in a self-registered manner, characterized in that a substrate region is provided at a major surface with a first masking layer having at least one opening or depression and the surface is provided at least at the area of the opening and on an adjoining part of the masking layer with a substantially uniform layer of the first material having a depression at the area of the opening, while the layer of the first material is covered by a substantially uniform layer of a second masking material and a substantially uniform layer of a first convertible material, and in that within the original opening in the first masking layer a depression in the layers of the second masking material and the first convertible material is maintained and selective conversion of the first layer of convertible material is effected for the formation of an intermediate mask, by means of which an opening is formed at least along the inner edge of the depression in the layer of the second masking material, after which the groove in the layer of the first material is obtained by means of the mask thus formed in the layer of the second masking material.
Claim 2
Independent Claim
225 words
A method of forming at least one narrow groove in a substantially uniform layer of a first material, in which the width of the groove is determined in a self-registered manner, characterized in that a substrate region is provided at a major surface with a first masking layer having at least one opening or depression and the surface is provided at least at the area of the opening and on an adjoining part of the masking layer with a substantially uniform layer of the first material having a depression at the area of the opening, while the layer of the first material is covered by a substantially uniform layer of a second masking material and a substantially uniform layer of a first convertible material, and in that within the original opening in the first masking layer a depression in the layers of the second masking material and the first convertible material is maintained and selective conversion of the first layer of convertible material is effected for the formation of an intermediate mask, by means of which an opening is formed at least along the inner edge of the depression in the layer of the second masking material, after which the groove in the layer of the first material is obtained by means of the mask thus formed in the layer of the second masking material.
Claim 3
Dependent Claim
63 words
A method as claimed in Claim 1, characterized in that the first convertible layer is covered by a substantially uniform layer of a third masking material, which is subjected to a selective etching treatment so that at least along the inner edge of the depression in the first convertible layer a third masking layer remains, which protects the first convertible layer against conversion.
Claim 4
Dependent Claim
53 words
A method as claimed in Claim 2, characterized in that the first convertible layer comprises polycrystalline semiconductor material, which is converted, except along the inner edge of the depression, by means of ion implantation into highly doped semiconductor material, which is substantially not attacked during the step of etching the original semiconductor material.
Claim 5
Dependent Claim
34 words
A method as claimed in Claim 2 or 3, characterized in that the third masking layer comprises one of the materials silicon oxide, silicon nitride, aluminium oxide, an oxynitride, aluminium, platinum, tungsten or molybdenum.
Claim 6
Dependent Claim
32 words
A method as claimed in Claim 3 or 4, characterized in that the polycrystalline semiconductor material acts as a doping source for doping the substrate material exposed within the opening with impurities.
Claim 7
Dependent Claim
51 words
A method as claimed in Claim 3, characterized in that the first convertible layer comprises a semi- conductor material and the third masking layer comprises an oxidation-preventing material, while the semiconductor material is locally converted into oxide by means of local oxidation and the remaining semiconductor material is removed by etching.
Claim 8
Dependent Claim
48 words
A method as claimed in Claim 3, characterized in that the first convertible layer comprises a semi- conductor material, which is converted, except along the inner edge of the depression, by silicidation into a silicide, which is substantially not attacked during the step of etching the semiconductor material.
Claim 9
Dependent Claim
19 words
A method as claimed in Claim 7, characterized in that a silicide of platinum, tungsten or molybdenum is formed.
Claim 10
Dependent Claim
53 words
A method as claimed in Claim 3, characterized inthat the first convertible layer comprises a semiconductor material, which is converted at least along a part of the inner edge of the depression by means of local oxidation into oxide, which is then removed so that the remaining semiconductor material constitutes the intermediate mask.
Claim 11
Dependent Claim
73 words
A method as claimed in Claim 9, characterized in that a substantially uniform layer of oxidation-preventing material and a second convertible layer are provided on the first convertible layer, in which the depression within the original opening in the first masking layer is maintained and selective conversion of the second convertible layer takes place for an auxiliary mask, by means of which an oxidation mask is defined in the layer of oxidation-preventing material.
Claim 12
Independent Claim
192 words
A method of providing at least one narrow groove in a substantially uniform layer of a first material, in which the width of the groove is determined in a self-registered manner, characterized in that a substrata region is provided at a major surface with a first masking layer having at least oneopening and the device is provided at least at the area of the opening and on an adjoining part of the masking layer with a substantially uniform layer of the first material having a depression at the area of the opening, wherein the layer of the first material is covered by a substantially uniform layer of a second masking material, the depressinn being maintained within the original opening in the first masking layer and selective conversion of the second masking layer taking place, while at least along the inner edge of the depression the second masking layer becomes less resistant to etching than the remaining part of the second masking layer so that after removal of this part less resistant to etching a mask is obtained, by means of which the groove in the layer of the first material is formed.
Claim 13
Independent Claim
192 words
A method of providing at least one narrow groove in a substantially uniform layer of a first material, in which the width of the groove is determined in a self-registered manner, characterized in that a substrata region is provided at a major surface with a first masking layer having at least oneopening and the device is provided at least at the area of the opening and on an adjoining part of the masking layer with a substantially uniform layer of the first material having a depression at the area of the opening, wherein the layer of the first material is covered by a substantially uniform layer of a second masking material, the depressinn being maintained within the original opening in the first masking layer and selective conversion of the second masking layer taking place, while at least along the inner edge of the depression the second masking layer becomes less resistant to etching than the remaining part of the second masking layer so that after removal of this part less resistant to etching a mask is obtained, by means of which the groove in the layer of the first material is formed.
Claim 14
Dependent Claim
64 words
A method as claimed in Claim 11, characterized in that the second masking layer is covered by a substantially uniform layer of a third masking material, which is subjected to a selective etching treatment so that at least along the inner edge of the depression in the second masking layer a third masking layer remains, which protects the second masking layer against selective conversion.
Claim 15
Dependent Claim
70 words
A method as claimed in Claim 11 or 12, characterized in that the second masking layer comprises silicon nitride, in which ions are implanted over a part of the surface, the silicon nitride being subjected to a heat treatment after the implantation, but before the etching treatment, as a result of which the implanted part of the layer becomes more resistant to etching than the non-implanted part of the layer.
Claim 16
Independent Claim
31 words
A method as claimed in any one of the preceding Claims, characterized in that the etching treatment is continued in order to obtain a narrow groove in the subjacent substrate region.
Claim 17
Dependent Claim
26 words
A method as claimed in Claim 14, characterized in that the substrate region is a semi-conductor region and the groove is filled entirely or in part.
Claim 18
Independent Claim
38 words
A method as claimed in any one of the preceding Claims, characterized in that the etching treatment for formingthe groove is carried out by bringing the layer to be eched into contact with the constituents of a plasma.
Claim 19
Independent Claim
80 words
A method as claimed in any one of the preceding Claims, of manufacturing a semiconductor body, characterized in that the first material comprises a semi-conductor material and the first masking material comprises a material protecting the semiconductor material against oxidation, while, after the groove has been etched down to the surface, the material located outside the depression and protecting against oxidation is removed and the groove is filled for the major part with oxide by oxidation of the semiconductor material.
Claim 20
Dependent Claim
28 words
A method as claimed in Claim 17, characterized in that, before the material protecting against oxidation is removed, the groove is filled for the major part with oxide.
Claim 21
Independent Claim
54 words
A method as claimed in one of Claims 17 or 18, characterized in that, after the groove has been closed by oxidation, at least a part of the first material left within the depression is removed down to the major surface and the space thus obtained is filled for the major part wiih oxide.
Claim 22
Independent Claim
42 words
A method as claimed in any one of Claims 17 to 19, of manufacturing a transistor, characterized in that the'groove encloses within the depression a semiconductor region and parts of the uniform layer are maintained at least alongthe edge of the depression.
Claim 23
Dependent Claim
81 words
A method as claimed in Claim 20 of manufacturing a bipolar transistor, characterized in that the semi- conductor region enclosed by the groove and parts of the uniform layer are doped along the edge of the depression with impurities causing the opposite conductivity type in a manner such that they act as a diffusion source for forming an emitter zone of the first conductivity type and a base contact zone of the second conductivity type opposite to the first conductivity type.
Claim 24
Dependent Claim
80 words
A method as claimed in Claim 20 manufacturing a bipolar transitor, characterized in that the semiconductor region enclosed by the groove that may be filled with oxide within the depression and the parts of the uniform layer along the edge of the depression are doped with impurities causing the opposite conductivity type in such a manner that they act as a diffusion source for a base contact zone, a base zone, an emitter zone and a collector contact zone, respectively.
Claim 25
Dependent Claim
65 words
A method as claimed in Claim 20 of manufacturing a MOS transistor, characterized in that the surface within the opening in the first masking layer is provided with gate oxide and in that for a connection contact of the source zone, after the groove has been closed by oxidation, the semiconductor region enclosed by the groove and the gate oxide laying below it are removed.
Claim 26
Dependent Claim
75 words
A method as claimed in Claim 23, characterized in that the starting material is a substrate region of a first conductivity type, which is provided within the ppening of the first masking layer with a gate region of a second conductivity type opposite to the first conductivity type at the area of the groove and in that the semiconductor region enclosed by the groove is provided with a source region of the first conductivity type.
Claim 27
Independent Claim
88 words
A method of manufacturing a capacitor, characterized in that a major surface of a substrate region of conductive material is provided with at least one depression with edges substantially at right angles to the surface and is then entirely covered by a convertible layer, the depression being maintained and selective conversion taking place for the formation of a mask for etching grooves into the conductive material, and in that the conductive material in the grooves and on the surface is convered successively by a dielectric and conductive material.
Claim 28
Independent Claim
88 words
A method of manufacturing a capacitor, characterized in that a major surface of a substrate region of conductive material is provided with at least one depression with edges substantially at right angles to the surface and is then entirely covered by a convertible layer, the depression being maintained and selective conversion taking place for the formation of a mask for etching grooves into the conductive material, and in that the conductive material in the grooves and on the surface is convered successively by a dielectric and conductive material.
Claim 29
Independent Claim
18 words
A device obtained by means of a method as claimed in any one of Claims 1 to 25.
References Cited (Backward Citations)
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