Polymer film metalization
Embodiments in accordance with the present invention eliminate the need for a subtractive metal patterning process to pattern the electrode above a ferroelectric polymer. Instead, a selective electroless deposition process is used. A conductive polymer is used as a seed layer for the electroless plating of the metal electrode. A cost saving is provided by eliminating the chemical costs associated with conventional resist removal processing. The methods also potentially eliminate the requirement for aggressive and environmentally unsafe chemical-based photoresist removal processes.
This application is a continuation of U.S. application Ser. No. 10/337,960 filed Jan. 6, 2003 titled “POLYMER FILM METALIZATION.”
FIELD OF THE INVENTIONThe present invention relates to semiconductor processing, and, more particularly, to lithographic techniques for metal patterning on a ferroelectric polymer layer.
BACKGROUND OF INVENTIONSemiconductor manufacture utilizes well known processes wherein multiple layers of various material, including semiconductor, insulator, and conductor layers, are selectively deposited and selectively removed using various deposition and material removing processes. One of those processes is used to create conductive traces to interconnect devices on the substrate. A plurality of electrically conductive traces is formed by photolithographic techniques.
One exemplary photolithographic technique involves forming a conformal layer of electrically conductive material over the dielectric layer and applying a photoresist layer over the electrically conductive material layer. The photoresist layer is photoactive, such that when exposed to light (usually ultraviolet light), the photoresist becomes insoluble (negative photoresist) in specific solvents. Light is projected through a template that shields specific areas of the photoresist while exposing other areas, thereby translating the pattern of the template onto the photoresist. After exposure, an appropriate solvent removes the desired portions of the photoresist. The remaining photoresist becomes a mask that remains on the electrically conductive material layer. The mask is used to expose areas of the electrically conductive material layer to be etched away while protecting the electrically conductive material that ultimately forms the electrically conductive traces.
A similar process is currently being used to provide conductive traces on a layer of ferroelectric polymer overlying a first conductive layer.
Improved methods are needed to remove photoresist material that has been exposed to a plasma etching process. The methods must have a low defect rate, not harm the underlying desired material layers, be reasonably economical, and not present a hazard to personnel and the environment.
BRIEF DESCRIPTION OF DRAWINGS
In the following detailed description, reference is made to the accompanying drawings which form a part hereof wherein like numerals designate like parts throughout, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims and their equivalents.
Embodiments in accordance with the present invention provide methods for removing resist material from conductive materials on a ferroelectric polymer layer. The methods do not incorporate a subtractive metal patterning process, eliminating the use of chemicals that can damage the underlying conductive layers.
It is readily apparent that the conductive layer 20 is not exposed to resist removal chemicals, preventing the possibility of damage to the conductive layer 20 due to chemical reactivity.
Embodiments in accordance with the present invention eliminate the need for a subtractive metal patterning process to pattern a conductive layer above a ferroelectric polymer. Instead, a selective electroless deposition process is used. A conductive polymer is used as a seed layer for the electroless plating of the metal layer. A cost saving is provided by eliminating the chemical costs associated with conventional resist removal processing. The methods also potentially eliminate the requirement for aggressive and environmentally unsafe chemical-based photoresist removal processes.
Although specific embodiments have been illustrated and described herein for purposes of description of the preferred embodiment, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent implementations calculated to achieve the same purposes may be substituted for the specific embodiment shown and described without departing from the scope of the present invention. Those with skill in the art will readily appreciate that the present invention may be implemented in a very wide variety of embodiments. This application is intended to cover any adaptations or variations of the embodiments discussed herein. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.
Claims
1. (canceled)
2. A method, comprising:
- forming a conductive polymer layer on a ferroelectric polymer layer;
- patterning the conductive polymer; and
- depositing a conductive layer on the patterned conductive polymer layer.
3. The method of claim 2, wherein said forming comprises forming the conductive polymer layer on the ferroelectric polymer layer using a spin deposition and cure process.
4. The method of claim 2, wherein said patterning comprises using photoresist spin deposition to form a layer of photoresist on the conductive polymer layer, and exposing predetermined areas of the photoresist to a curing process.
5. The method of claim 2, wherein said patterning comprises using lithography and plasma etch processes to pattern the conductive polymer.
6. The method of claim 2, wherein said depositing comprises using an electroless plating process to deposit the conductive layer on the patterned conductive polymer layer.
7. The method of claim 6, wherein said using an electroless plating process includes optimizing the deposition process to minimize conductive layer deposition on the sidewalls of the conductive polymer.
8. A method for making a semiconductor substrate comprising:
- providing a substrate including a ferroelectric polymer layer;
- forming a conductive polymer layer on the ferroelectric polymer layer;
- patterning the conductive polymer layer; and
- depositing a conductive layer on the patterned conductive polymer layer.
9. The method of claim 8, wherein said forming comprises forming a conductive polymer layer on the ferroelectric polymer layer using a spin deposition and cure process.
10. The method of claim 8, wherein said patterning comprises using photoresist spin deposition to form a layer of photoresist on the conductive polymer layer, and exposing predetermined areas of the photoresist to a curing process.
11. The method of claim 8, wherein said patterning comprises using lithography and plasma etch processes to pattern the conductive polymer.
12. The method of claim 8, wherein said depositing comprises using an electroless plating process to deposit the conductive layer on the patterned conductive polymer layer.
13. The method of claim 12, wherein said using an electroless plating process includes optimizing the deposition process to minimize conductive layer deposition on the sidewalls of the conductive polymer.
14. A method for making a semiconductor substrate comprising:
- providing a substrate including a patterned conductive polymer layer on top of the substrate; and
- depositing a conductive layer on top of the patterned conductive polymer layer.
15. The method of claim 14, wherein said providing comprises providing a substrate including a ferroelectric polymer layer underneath the patterned conductive polymer layer.
16. The method of claim 14, wherein said providing comprises of forming a conductive polymer layer on the substrate and patterning the conductive polymer layer using lithography and etch processes.
17. The method of claim 14, wherein said depositing comprises using an electroless plating process to deposit the conductive layer on top of the patterned conductive polymer layer.
18. The method of claim 17, wherein said using an electroless plating process includes optimizing the deposition process to minimize conductive layer deposition on the sidewalls of the conductive polymer.
Type: Application
Filed: Apr 21, 2005
Publication Date: Aug 25, 2005
Inventors: Ebrahim Andideh (Portland, OR), Daniel Diana (Portland, OR)
Application Number: 11/112,287