Motorola Corporation

Willis R Goodner

John L Freeman, Jr

Yefim Bukhman

Andrew G Nagy

Raymond J Balda

James N Smith

G Scot Srodes

John Horvath

Joseph P Kao

A residue-free plasma etch of high temperature aluminum copper metallization is provided by the use of a single plasma etcher. The metallization layer is covered by a protective oxide layer. This structure is then placed in the single etcher and a vacuum is established. The protective oxide layer is then etched and without breaking the vacuum or removing the structure from the etcher the metal layer is also etched. This results in the etched surface being residue-free.

Residue-free plasma etch of high temperature AlCu

A method is described for providing a conductive pillar in a via between multiple layers of conductors on planar electronic structures such as integrated circuits while at the same time exposing other large area contact regions such as a bonding pad. A first conductor layer is formed on the device substrate, etched to delineate the bonding pad and the first level interconnects, and covered with a differentially etchable intermediate conductive material which is delineated to form the conductive pillar. A dielectric planarizing layer is applied so as to have a smooth surface contour and a lower thickness above the conductive pillar than over the first level interconnects or the bonding pad. The planarizing dielectric is desirably a negative acting radiation sensitive material such as a polyimide. A mask is used to render the portions of this dielectric planarizing layer above the bonding pad soluble so that it may be dissolved away while leaving the remainder undisturbed. The resulting structure is then blanket etched to remove the smaller thickness of dielectric layer above the top of the pillar. The dielectric surface and pillar surface smoothly join. Another conductive layer is then applied over the surface of the dielectric planarizing layer and in contact with the top of the pillar and patterned in the conventional manner to form the second level interconnects. The resulting structure has a relatively smooth surface topology and little or no step at the pillars.

Pillar via process

A process is disclosed for fabricating semiconductor devices, and especially for fabricating semiconductor devices having multiple levels of metallization separated by polyimide or other organic materials. The process avoids the sputter etching and redeposition of the lower metal layer during reactive ion etching of openings through the organic layer. Sequential layers overlying the first layer of metallization include a layer of oxide, a layer of organic material, and a second layer of oxide. The second layer of oxide functions as a hard mask for patterning the organic material. The first layer of oxide acts as an etch stop and protective layer to prevent attack of the underlying metal during reactive ion etching of the organic layer. The first layer of oxide is of limited areal extent to avoid subsequent problems with the organic layer. The oxide located at the bottom of the opening through the organic material as well as the second layer of oxide and any oxide which is sputtered and redeposited on the walls of the opening through the organic material are easily removed in a single etch step without adversely affecting the underlying metallization. After removing the oxide, a second layer of metallization is applied and patterned as required.

Process for fabricating semiconductor device

A holder and method for controlling and uniformly maintaining the temperature of work pieces when the work pieces are acted upon by a plasma in a plasma reactor apparatus. Support means which hold the work pieces so as to expose them to the reactive plasma also position metallic plate members which are capable of being heated to an elevated temperature by the plasma when in electrical contact with an electrode of the plasma reactor apparatus. The metallic plate members are all electrically shorted together, but are insulated from the support means. A temperature sensitive switch connects the metallic plate members to an electrode of the plasma apparatus. Work pieces to be acted upon by the plasma are placed in proximity to the metal plate members. In the presence of a plasma and when shorted to the apparatus electrode, the metallic plate members are rapidly heated and heat is conducted to the work pieces to heat them uniformly. The temperature of the work pieces is controlled by selectively opening and closing the temperature sensitive switch and thereby selectively shorting the metal members to the apparatus electrode. Little heating occurs when the switch is open and the members are isolated from the electrode.

Workpiece holder and method for plasma reactor apparatus

Improved stabilization of 1,1,1-trichloroethane is obtained by employing a free radical scavenger as a stabilizer which will trap trichloromethyl radicals, making them unavailable for formation of acidic species in the trichloroethane. Examples of such free radical scavengers include trichloroethylene, tetrachloroethylene, or fluorene. Compositions in accordance with the invention consist essentially of the 1,1,1-trichloroethane and from about 0.1 volume percent to about 5 volume percent of the free radical scavenger. In the fabrication of semiconductor devices in which the so stabilized trichloroethane is employed as a degreasing solvent, the acidity of the trichloroethane composition may be monitored, and additional free radical scavenger added to the solution to maintain the acidity within acceptable limits, thus allowing the trichloroethane to be used indefinitely.

Growing community of inventors

Chandler, AZ, United States of America

Willis R Goodner