Method for forming a metal contact
AssigneeSGS-Thomson Microelectronics S.A.
InventorsFusen E. Chen, Fu-Tai Liou, Yih-Shung Lin, Girish A. Dixit, Che-Chia Wei
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Abstract
A method is provided for depositing aluminum thin film layers to form improved quality contacts in a semiconductor integrated circuit device. All or some of the deposition process occurs at relatively low deposition rates at a temperature which allows improved surface migration of the deposited aluminum atoms. Aluminum deposited under these conditions tends to fill contact vias without the formation of voids. The low temperature deposition step can be initiated by depositing aluminum while a wafer containing the integrated circuit device is being heated from cooler temperatures within the deposition chamber.
Claims19
A method for depositing an aluminum layer on a semiconductor integrated circuit, comprising the steps of:
- increasing the temperature of the integrated circuit to a temperature less than approximately 500.degree. C.;
- and
- beginning to deposit aluminum on the integrated circuit simultaneously with the increase in the temperature at a rate which is low enough to allow surface migration of deposited aluminum to fill low regions in the integrated circuit.
A method for forming an aluminum contact in an integrated circuit, comprising the steps of:
- forming an insulating layer over a conducting layer;
- forming an opening through the insulating layer to expose a portion of the conducting layer;
- raising the temperature of the integrated circuit from below approximately 350.degree. C. to a value between approximately 400.degree. C. and approximately 500.degree. C.;
- during said temperature raising step, depositing aluminum continuously on the integrated circuit, wherein the depositing aluminum step begins simultaneously with the beginning of the temperature raising step;
- after said temperature raising step, continuing to deposit an aluminum layer on the integrated circuit to a desired thickness;
- during said desired thickness depositing step, controlling the rate at which aluminum is deposited to allow deposited aluminum to migrate into the opening so as to provide a substantially complete fill thereof.
A method for forming an aluminum contact in an integrated circuit, comprising the steps of:
- forming an insulating layer over a conducting layer;
- forming an opening through the insulating layer to expose a portion of the conducting layer;
- forming a barrier layer over the insulating layer, in the opening and the exposed portion of the conducting layer;
- beginning to deposit aluminum at a temperature below approximately 350.degree. C. on the barrier layer at a relatively low rate of deposition;
- simultaneously with said beginning to deposit aluminum step, beginning to raise the temperature of the integrated circuit;
- continuing to deposit aluminum while increasing the temperature from below approximately 350.degree. C. to a desired temperature between approximately 400.degree. C. and approximately 500.degree. C.;
- after the integrated circuit temperature has reached the desired temperature, depositing an aluminum layer on the integrated circuit to a desired thickness;
- during said desired thickness depositing step, controlling the rate at which aluminum is deposited to allow deposited aluminum to migrate into the opening so as to provide a substantially complete fill thereof.
Dependencies are inferred from the claim text.