Method for controlling the conductivity of polyimide films and improved devices utilizing the method
AssigneeMotorola, Inc.
InventorGraham P. Gill
Life of this patent
Estimating the term…
Abstract
When ion bombardment milling is used to each electronic devices having metal-polymer sandwich stuctures, the ion bombardment induces conductivity in the normally insulating polymer layers, even at low (e.g. 100 eV) bombardment energies. Bombarded polymer layers can be used to produce thin film resistors. Where it is desired to reduce or eliminate the bombardment induced conductivity, this may be accomplished, for a polyimide polymer, by a brief (e.g. 30 sec) exposure to a low energy (e.g.<10 eV) plasma, or by heating for a longer period of time (e.g 2 hours at 250.degree. C.), or by a combination thereof. It is desirable that the plasma contain oxygen.
Claims20
A method for preparing a structure which includes a conductor and an insulating dielectric on a substrate, comprising:
- depositing a polymer layer to a predetermined thickness on said substrate, said polymer layer having the property of becoming substantially non-insulating when exposed to energetic particles;
- forming on said polymer layer a conductor layer;
- creating on said conductor layer a pattern determining layer to provide a covered portion and a non-covered portion of said conductor layer;
- etching said non-covered portion of said conductor layer by exposure to said energetic particles, to form said conductor;
- continuing until substantially all said conductor layer in said non-covered portion is removed and an underlying region of said polymer layer is exposed to said energetic particles and thereby rendered substantially non-insulating;
- and
- exposing thereafter said region of said polymer layer to a low energy gaseous plasma to return said polymer layer to a substantially insulating state to form said insulating dielectric.
A method for preparing a structure which includes a first and second conductor and an insulating dielectric on a substrate, comprising
- depositing a first polymer layer to a first predetermined thickness on said substrate, said first polymer layer having the property of becoming substantially non-insulating when exposed to energetic particles;
- forming on said first polymer layer a first conductor layer;
- creating on said first conductor layer a first pattern determining layer to provide a first covered portion and a first non-covered portion of said first conductor layer;
- etching said first non-covered portion of said first conductor layer by exposure to said energetic particles to form said first conductor;
- continuing until substantially all said first conductor layer in said first non-covered portion is removed and an underlying first region of said first polymer layer is exposed to said energetic particles and thereby rendered substantially non-insulating;
- exposing thereafter said first region of said first polymer layer to a low energy gaseous plasma to return said first polymer layer to a substantially insulating state to form a first part of said insulating dielectric;
- depositing a second polymer layer to a second predetermined thickness on said substrate, said second polymer layer having the property of becoming substantially non-insulating when exposed to said energetic particles;
- forming on said second polymer layer a second conductor layer;
- creating on said second conductor layer a second pattern determining layer to provide a second covered portion and a second non-covered portion of said second conductor layer;
- etching said second non-covered portion of said second conductor layer by exposure to said energetic particles to form said second conductor;
- continuing until substantially all said second conductor layer in said second non-covered portion is removed and an underlying second region of said second polymer layer is exposed to said energetic particles and thereby rendered substantially non-insulating;
- and
- exposing thereafter said second region of said second polymer layer to a low energy gaseous plasma to return said second polymer layer to a substantially insulating state to form a second part of said insulating dielectric.
In a process for fabricating electronic devices utilizing a pattern of conductor regions in contact with a polymer layer, wherein portions of said polymer layer have been exposed to energetic particles, the improvement comprising, thereafter exposing said portions of said polymer layer to a low energy gaseous plasma.
In a process for fabricating electronic devices utilizing a pattern of conductor regions in contact with a polymer layer, wherein portions of said polymer layer have been exposed to energetic particles during an etching step, the improvement comprising, thereafter exposing said portions of said polymer layer to a low energy gaseous plasma.
In a process for fabricating electronic devices utilizing a substantially non-conductive polymer layer, wherein at least portions of said polymer layer have been exposed to energetic particles and rendered partially conductive, the improvement comprising:
- exposing at least some of said portions of said polymer layer to a low energy gaseous plasma to restore some of said portions to a substantially non-conductive state.
A method for making a partially conducting region on a substrate, comprising, creating a polymer layer on said substrate, and bombarding a portion of said polymer layer with a predetermined dose of energetic particles to form said partially conducting region, wherein said energetic particles have an energy in the range 100 to 2000 eV.
A method for making a partially conducting region of a predetermined value of conductivity on a substrate, comprising:
- forming a polymer layer on said substrate to a predetermined thickness;
- bombarding a portion of said polymer layer with a predetermined dose of energetic particles to form, in said polymer layer, a partially conducting region having a conductivity greater than said predetermined value;
- and
- exposing at least a part of said region to a low energy gaseous plasma for a predetermined time to reduce said conductivity to said predetermined value.
A method for making a partially conducting region of a predetermined value of conductivity on a substrate, comprising:
- forming a polymer layer on said substrate to a predetermined thickness;
- bombarding a portion of said polymer layer with a predetermined dose of energetic particles to form, in said polymer layer, a partially conducting region having a conductivity greater than said predetermined value;
- and
- heating said region to a predetermined temperature less than a thermal decomposition temperature for said polymer for a predetermined time, to reduce said conductivity to said predetermined value.
A method for making, on a substrate, a layer having conducting and non-conducting portions, comprising:
- forming a polymer layer on said substrate;
- bombarding said polymer layer with energetic particles to induce conductivity in substantially the entire lateral extent of said polymer layer;
- covering said polymer layer with a masking layer which is substantially impervious to a low energy gaseous plasma, and containing an aperture portion where conductivity is not desired and a blocking portion where conductivity is desired;
- and
- exposing said covered polymer layer to a low energy gaseous plasma to substantially remove conductivity in said polymer layer in said aperture portions.
A method for making, on a substrate a layer having conducting and non-conducting portions, comprising:
- forming a polymer layer on said substrate to a predetermined thickness;
- covering said polymer layer with a masking layer substantially impervious to energetic particles and having apertures where conductivity is desired in said polymer layer and blocking portions where conductivity is not desired in said polymer layer;
- and
- bombarding said polymer layer with energetic particles through said apertures to induce conductivity therein.
Dependencies are inferred from the claim text.