Microelectronic process and structure
View Patent ↗The present invention relates to a process for integrating air as dielectric in semiconductor devices, comprising the steps of: a. applying a layer of a dielectric ( 2 ) which is to be patterned to a substrate ( 1 ); b. patterning the dielectric layer ( 2 ) which has been applied; c. applying a conductor metal ( 3 ) for the patterned dielectric layer ( 2 ) and forming a common surface from the conductor metal ( 3 ) and the dielectric ( 2 ); d. applying a layer of an organic dielectric ( 4 ) to the layer produced in step c.; and e. bringing the coated substrate produced in this way into contact with a fluorine-containing compound in order to form an arrangement which has air as dielectric between conductor structures and has a continuous dielectric layer ( 4 ) on the top side, and to a semiconductor device with air layers as dielectric produced using this process.
1. Process for integrating air as dielectric in semiconductor devices, comprising the steps of:
a. applying a layer of silicon dioxide as a dielectric patterned to a substrate;
b. patterning the applied dielectric layer;
c. applying a conductor metal for the patterned dielectric layer and forming a common surface from the conductor metal and the dielectric;
d. applying a layer of an organic dielectric to the layer produced in step c.; and
e. bringing the coated substrate produced in this way into contact with a fluorine-containing compound in order to form an arrangement which has air as dielectric between conductor structures and has a continuous dielectric layer on the top side.
2. Process according to claim 1 , wherein the fluorine-containing compound is in gas form.
3. Process according to claim 1 , wherein the fluorine-containing compound is a fluorine-containing hydrocarbon compound with 1–4 C atoms, a perfluorinated hydrocarbon compound with 1–4 C atoms, a fluorine-containing nitrogen compound with 1–2 N atoms, a chlorofluorocarbon compound with 1–4 C atoms, and/or HF, F 2 , BF 3 , PF 3 , ClF, ClF 3 , ClF 5 , XeF 2 , SF 4 , SO 2 F 2 , SF 6 or a mixture thereof.
4. Process according claim 1 , wherein the fluorine-containing compound is one or more of the following compounds: CF 4 , CHF 3 , CH 3 F, C 2 F 6 , CH 2 F 2 , C 2 H 2 F 4 , C 2 Cl 2 F 4 , C 2 Cl 3 F 3 , C 2 ClF 5 , C 2 Cl 4 F 2 , and/or NF 3 .
5. Process according to claim 1 , wherein the fluorine-containing compound is present in the form of a mixture with NH 3 , O 2 and/or H 2 O.
6. Process according to claim 1 , wherein the fluorine-containing compound is used in the form of a solution.
7. Process according to claim 6 , wherein the fluorine-containing compound is present in the form of an aqueous solution of HF, KF, NaF, LiF, NH 4 HF 2 or NH 4 F or mixtures thereof.
8. Process according to claim 1 , wherein the step of bringing the substrate into contact with the fluorine-containing gaseous compound takes place at 20–200° C.
9. Process according to claim 1 , wherein the step of bringing the substrate into contact with the fluorine-containing compound is carried out over 5–60 min.
10. Process according to claim 1 , wherein the substrate is selected from the group consisting of silicon, germanium, microelectronically processed Si or Ge substrates; glass, metal-glass combinations; or Si or Ge with electrically semiconducting polymers.
11. Process according to claim 1 , wherein copper, silver, aluminum or alloys of Al, Cu and Si is used as conductor metal.
12. Process according to claim 1 , wherein copper is used as conductor metal.
13. Process according to claim 1 , wherein one or more of the following compounds which are known per se are used as organic dielectric: polybenzoxazoles (PBO), polybenzimidazoles, polyimides (PI), and/or precursors thereof, polyquinoxalines, polyarylenes, fluorinated or unfluorinated polyarylene ethers, polynaphthyl ethers, each of which compounds may contain silicon-, germanium-, boron- or phosphorus-containing organometals.
14. Process according to claim 1 , wherein the organic dielectric used is a photosensitive dielectric, photosensitive polybenzoxazole or photosensitive benzocyclobutene.
15. Process according to claim 1 , wherein after step c. a planarization step is carried out.
16. Process according to claim 1 , wherein steps a. to d. are carried out repeatedly before the step of bringing the substrate into contact with the fluorine-containing compound, so that a multilayer structure is brought into contact with the fluorine-containing compound.
17. Process according to claim 1 , wherein a barrier layer is applied before the conductor metal is applied.
18. Process according to claim 1 , wherein the barrier layer is made from one or more of the following materials: titanium, titanium nitride, tantalum, tantalum nitride, tungsten nitride, tungsten carbide, silicon carbide, amorphous carbon and mixtures or compounds of these materials with oxygen, carbon and/or hydrogen.
19. Process according to claim 1 , wherein the surface of the conductor metal is passivated before the organic dielectric is applied.
20. Process according to claim 1 , wherein mechanical support elements are integrated in order to increase the mechanical strength of the air-dielectric layer.