JPS5818774B2 - Method for selectively forming a conductive layer on a substrate having convex portions - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for selectively forming a conductive layer on a top surface of a convex portion of a substrate such as a semiconductor or dielectric substrate having a convex portion. This invention relates to an improvement in a method for forming a conductive layer.

In the conventional method of forming a selective conductive layer on a substrate having such convex portions, the photoresist layer is usually exposed to light by applying an optical mask. In addition to requiring a highly matched optical mask, it is troublesome to accurately position the optical mask over the top surface of the convex portion of the substrate in the photoresist layer, and this problem becomes more difficult as the top surface of the convex portion of the substrate becomes finer. Even more so.

Therefore, the present invention provides a conductive layer on the top surface of the convex portion of the substrate by easily performing an exposure process on the photoresist layer without applying an optical mask and without having to accurately position the optical mask with respect to the photoresist layer. When exposed to a rubber photoresist agent containing diazide as a photosensitizer such as KTFR or KMERl (both products manufactured by Kodak Company), the light N5-R-N3→ : N-R-N: +2N2...
...As shown in the chemical equation (1), generally N
Diamide represented by the chemical formula 5-R~N3 undergoes a photochemical reaction to generate N2 gas and is generally converted to nitrene represented by the chemical formula N-R-N, and as shown by the chemical equation: It exhibits a crosslinking reaction in which it is added to the double bond of the nitre molecule, which is represented by the chemical formula N-R-N, and crosslinks rubber molecules.
As a result, the rubber molecules are reticulated, and the exposed rubber photoresist agent is dissolved in a developer for the rubber photoresist agent (KTFRDEVELOPER (trade name, manufactured by Kodak) if the rubber photoresist agent is the above-mentioned KTFR). Although it becomes difficult to eliminate, if the photochemical reaction shown by the above formula (1) is performed in an oxygen atmosphere or an atmosphere containing oxygen, :N-R-N: +0□→0N-R-NO...・・・
...Nitrene is oxidized as shown in the chemical equation (3), and therefore the chemical reaction shown in equation (1) is performed or not in an oxygen atmosphere or an oxygen-containing atmosphere, as described above. This was done by focusing on the fact that there is a difference in the crosslinking reaction represented by formula (2), in the former case the crosslinking reaction is suppressed.

Note that R in the above formulas (1) to (3) is given when the rubber photoresist agent is KTFR, and is represented by N5-R-N3 when R is given by formula (4). Diazide is “2.
6-bis(P-azidobenzilitine)-4-methylcyclohexanone” (2,6-bis(P-azidobenzilitine)-4-methylcyclohexanone
enzylidene) -4-methylcy
clo-hexanon).

Embodiments of the present invention will be described in detail below with reference to the drawings.
G shows an example of selectively forming a conductive layer on the top surface of a convex part of a substrate having a convex part, and FIG.
As shown in FIG.
A conductive layer 3 is deposited with substantially equal thickness on each part by a suitable means such as vapor deposition or sputtering, and then a rubber-based photoresist containing diazide as a photosensitive agent is deposited on this conductive layer 3 as shown in Figure C, for example as described above. Similarly, a layer 4 made of KTFR is applied to each part to a substantially equal thickness, for example, by coating means, and then a transparent flat plate 5 such as a glass plate is used to locally coat it as shown in the figure. The photoresist layer 4 is placed facing the substrate 2 so as to be in contact with the portion 4a on the top end surface 1a of the convex portion 1 of the substrate 2; The photoresist layer 4 is exposed to light through the flat plate 5, and then the photoresist layer 4 is developed (in this case, when the layer 4 is made of KTFR, the above-mentioned KTFR DEVELOPER is used as the developer).

In this way, during the above-mentioned exposure process, the transparent flat plate 5 is in contact with the portion 4a of the layer 4, so that almost no oxygen acts on this portion 4a, or the action of oxygen does not affect the layer 4. This part 4a
Therefore, in the crosslinking reaction of the layer 40 parts 4a and 4b after exposure treatment, which is expressed by the above-mentioned formula (3), the latter layer 4a has a difference in the crosslinking reaction in the form that the crosslinking reaction is suppressed. Therefore, after the above-described development process, the photoresist layer 4 is dissolved away from above the conductive layer 3, leaving a portion 4a, as shown in FIG.

Therefore, the conductive layer 3 is then subjected to an etching process by applying an etchant thereto as usual.
As shown in FIG. The resist is removed from the top of the substrate 2 by leaving it as it is, and then applying a so-called resist stripper liquid (for example, 1, R, C, L, J-100 manufactured by Co., Ltd.) to the rear part 4a (exposed) to remove the resist. By carrying out the treatment and removing the portion 4a from above the conductive layer portion 3a as shown in Figure G, a selective conductive layer 3a is formed on the top end surface 1a of the protrusion 1 of the substrate 2. It becomes.

According to the example of the present invention described above, as shown in FIG. Since 3a is obtained without applying an optical mask, the above-mentioned example of the present invention eliminates the drawbacks mentioned at the beginning of the conventional method of selectively forming a conductive layer by applying an optical mask. It has the characteristics of a dog.

[Brief explanation of the drawing]

Figures A to G are process diagrams showing an example of a method for forming a selectively conductive layer on a substrate having convex portions according to the present invention. In the figure, 1 is a convex part, 2 is a substrate, 3 is a conductive layer, 3a is a conductive layer part, 4 is a rubber resist layer, 4a and 4b are rubber resist layer parts, and 5 is a transparent flat plate. Show each.

Claims (1)

[Claims] 1. A conductive layer is deposited on a substrate having convex portions with approximately the same thickness at each portion, and then a rubber-based photoresist layer containing diazide as a photosensitive agent is deposited onto the conductive layer at approximately the same thickness at each portion. Next, a light-transmitting flat plate is placed facing the substrate such that it locally contacts the top surface of the convex portion of the substrate of the rubber-based photoresist layer, and is exposed to an oxygen atmosphere or an oxygen atmosphere. The rubber-based photoresist layer is exposed to light through the light-transmitting flat plate in an atmosphere containing The conductive layer is dissolved away from above, leaving a portion on the top surface of the convex portion of the substrate, and then the conductive layer is treated with an etchant to remove the conductive layer from the top of the convex portion of the substrate. The rubber-based photoresist layer is dissolved away from the substrate, leaving a portion on the top surface with the rubber-based photoresist layer disposed thereon, and then the conductive layer left on the top surface of the convex portion of the substrate is coated. A method for selectively forming a conductive layer on a substrate having a convex portion, characterized in that the rubber-based photoresist layer disposed on the substrate is removed and a conductive layer is selectively formed on the top surface of the convex portion of the substrate. Conductive layer formation method.