What is claimed is:
1. A method of manufacturing a semiconductor device comprising the steps of:
(a) forming a capacitor electrode metal film mainly made of one of Pt and Ir on an underlying layer;
(b) forming a first mask film mainly made of one of Ru and Os on said capacitor electrode metal film;
(c) selectively opening said first mask film;
(d) exposing an uncovered part of said capacitor electrode metal film at an opening of said first mask film to a predetermined gas atmosphere so as to volatilize while heating said capacitor electrode metal film, thereby selectively etching said capacitor electrode metal film; and
(e) removing said first mask film.
2. The method according to claim 1, wherein
said capacitor electrode metal film is a lower electrode metal film of a capacitor,
said method further comprising the steps of:
(f) after said step (e), forming a dielectric film covering said lower electrode metal film; and
(g) forming, on said dielectric film, an upper electrode insulated from said lower electrode metal film by said dielectric film.
3. The method according to claim 2, wherein
a conductive plug is formed in said underlying layer and a first metal film is formed on said underlying layer to be in contact with said conductive plug, and
in said step (a), said lower electrode metal film is formed to be connected to said conductive plug with said first metal film interposed therebetween.
4. The method according to claim 3, wherein
a second metal film is further formed on said first metal film, said second metal film containing at least one material selected from the group consisting of metal oxide, metal nitride, metal silicide, metal oxynitride, metal silicon-oxide, metal silicon-oxynitride and metal silicon-nitride, and
in said step (a), said lower electrode metal film is formed to be connected to said first metal film with said second metal film interposed therebetween.
5. The method according to claim 3, further comprising the step of
(h) in advance of said step (f), forming a contact-preventing metal film preventing contact between said dielectric film and said first metal film.
6. The method according to claim 1, further comprising the step of
(i) in advance of said step (b), forming a first metal film on said capacitor electrode metal film, said first metal film containing at least one material selected from the group consisting of metal oxide, metal nitride, metal silicide, metal oxynitride, metal silicon-oxide, metal silicon-oxynitride and metal silicon-nitride, and
in said step (b), said first mask film is formed on said capacitor electrode metal film with said first metal film therebetween.
7. The method according to claim 1, wherein
said step (c) includes the steps of:
(c-1) forming a second mask film containing at least one of silicon oxide and silicon nitride on said first mask film;
(c-2) patterning said second mask film by photolithography and etching; and
(c-3) selectively etching said first mask film using said second mask film as an etching mask, thereby selectively opening said first mask film.
8. The method according to claim 7, wherein
said step (c) further includes the step of
(c-4) in advance of said step (c-1), forming a first metal film on said first mask film, said first metal film containing at least one material selected from the group consisting of metal oxide, metal nitride, metal silicide, metal oxynitride, metal silicon-oxide, metal silicon-oxynitride and metal silicon-nitride, and
in said step (c-1), said second mask film is formed on said first mask film with said first metal film therebetween.
9. The method according to claim 7, wherein
in said step (c-2), said second mask film as patterned is subjected to isotropic etching.
10. The method according to claim 1, further comprising the step of
(j) after said step (c), performing isotropic etching on said first mask film.
11. The method according to claim 1, wherein
an etching stopper film mainly made of one of Ru and Os is formed on said underlying layer,
in said step (a), said capacitor electrode metal film is formed on said etching stopper film, and
in said step (d), said etching stopper film is used as an etching stopper in etching said capacitor electrode metal film.
12. The method according to claim 11, wherein
a first metal film is formed on said etching stopper film, said first metal film containing at least one material selected from the group consisting of metal oxide, metal nitride, metal silicide, metal oxynitride, metal silicon-oxide, metal silicon-oxynitride and metal silicon-nitride, and
said capacitor electrode metal film is formed on said etching stopper film with said first metal film therebetween.
13. The method according to claim 11, wherein
said capacitor electrode metal film is a lower electrode metal film of a capacitor,
said method further comprising the steps of:
(f) after said step (e), forming a dielectric film covering said lower electrode metal film;
(g) forming, on said dielectric film, an upper electrode insulated from said lower electrode metal film by said dielectric film; and
(k) in advance of said step (f), forming a contact-preventing metal film preventing contact between said dielectric film and said etching stopper film.
14. The method according to claim 2, wherein
said step (g) includes the steps of:
(g-1) forming, on said dielectric film, an upper electrode metal film insulated from said lower electrode metal film by said dielectric film;
(g-2) forming a third mask film mainly made of one of Ru and Os on said upper electrode metal film;
(g-3) selectively opening said third mask film; and
(g-4) exposing an uncovered part of said upper electrode metal film at an opening of said third mask film to a predetermined gas atmosphere so as to volatilize while heating said upper electrode metal film, thereby selectively etching said upper electrode metal film.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for determining the thickness of a layer of lacquer which is applied by electrophoretic immersion coating to an article, wherein the article for immersion coating is immersed in a lacquer immersion bath containing lacquer and forms an electrode which generates, together with at least one counter electrode, an electrical field comprising the following steps:
a) determining the electrical charge flowing through the article during immersion coating
b) determining the surface of the article exposed to the lacquer,
c) determining the thickness of the layer of lacquer based on the electrical charge determined in step a) and the surface determined in step b).
2. The method of claim 1, wherein the electric current flowing through the article during immersion coating is measured for determining the electric charge in step a).
3. The method of claim 1, wherein the surface of the article is determined in step b) using the maximum starting current which flows through the article at the start of immersion coating.
4. The method of claim 1 wherein the thickness of the layer of lacquer is determined in step c)by taking into account the temperature of the lacquer.
5. The method of claim 1, wherein the thickness of the layer of lacquer is determined in step c)by taking into account the pH of the lacquer.
6. The method of claim 1, wherein the thickness of the layer of lacquer is determined in step c)by taking into account the electrical conductivity of the lacquer.
7. The method of claim 1, wherein the thickness of the layer of lacquer is determined in step c)by taking into account the solids content of the lacquer.
8. The method of claim 1, wherein the thickness of the layer of lacquer is determined in step c)by taking into account the density of the lacquer.
9. The method of claim 1, wherein the thickness of the layer of lacquer is determined in step c)by taking into account the spacing between the article and the at least one counter electrode (16, 18).
10. The method of claim 1, wherein the voltage applied between the electrode and the at least one counter electrode (16, 18) is controlled in such a way that the starting current at the start of immersion coating at least approximately matches a predetermined value.
11. The method of claim 10, wherein the predetermined value depends on parameters of the lacquer.
12. The method of claim 1, wherein the immersion coating is finished as soon as the determined layer thickness has reached a predeterminable target value.
13. A system for determining the thickness of a layer of lacquer which is applied by electrophoretic immersion coating to an article, comprising:
an immersion bath for receiving a lacquer in which the article can be immersed,
a voltage source, of which one pole can be connected to the article and of which the other pole is connected to at least one counter electrode (16, 18) reaching into the immersion bath,
a charge measurement apparatus for determining the electrical charge flowing through the article during immersion coating,
a computer which determines the thickness of the layer of lacquer from the charge measured by the charge measurement apparatus and the surface of the article exposed to the lacquer.
14. The system of claim 13, wherein the charge measurement apparatus comprises an ammeter.
15. The system of claim 13, wherein the maximum starting current which flows through the article at the start of immersion coating, can be stored in the computer.
16. The system of claim 15, wherein the computer determines the surface of the article exposed to the lacquer from the maximum starting current.
17. The system of claim 13, comprising a temperature sensor, which is connected to the computer, for determining the temperature of the lacquer.
18. The system of claim 13, comprising a pH sensor, which is connected to the computer, for measuring the pH factor of the lacquer.
19. The system of claim 13, comprising a conductivity sensor, which is connected to the computer, for measuring the conductivity of the lacquer.
20. The system of claim 13, comprising a sensor, connected to the computer, for determining the solids content of the lacquer.
21. The system of claim 13, comprising a density sensor, which is connected to the computer, for measuring the density of the lacquer.
22. The system of claim 13, comprising a control device which is configured to control the voltage applied between the electrode and the at least one counter electrode in such a way that the starting current at the start of immersion coating has a predetermined value.
23. The system of claim 13, comprising a controller which is configured to terminate the immersion coating as soon as the specific lacquer thickness has reached a predeterminable target value.