# US 5,707,894 A · Bonding pad structure and method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,707,894 A - Document ID: US5707894A - Status: Granted - Kind: A - Application number: 08/549,629 - Filed: 1995-10-27 - Granted: 1998-01-13 - Earliest claimed: 1995-10-27 - Assignees: United Microelectronics Corp. - Inventors: Ming-Shan Hsiao - Web page: https://patentgrep.com/patent/US5707894A ## CPC - H10W 72/019: {of bond pads} - H10W 72/075: {of bond wires} - H10W 72/536: {the connected ends being ball-shaped} - H10W 72/59: Bond pads specially adapted therefor - H10W 72/934: {Cross-sectional shape, i.e. in side view} - H10W 72/951: {Materials of bond pads} - H10W 72/952: {comprising metals or metalloids, e.g. PbSn, Ag or Cu} - H10W 72/983: {Reinforcing structures, e.g. collars} - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract A structure and a process for forming an improved bonding pad which resists bond pad peeling of between the bonding pad layer and the underlying layers. The method comprises forming plurality of anchor pads on said substrate surface in a bonding pad area. Next, a first insulating layer is formed over said substrate surface and the anchor pads. Vias are formed through the first insulating layer. The vias are filled with a second metal layer making a connection to the anchor pads and the first insulating layer is covered in the bonding pad area with the second metal layer. It is important that the via holes have a smaller cross sectional area than the anchor pads so that the combination of the anchor pads and the second metal form small "hooks" into the first insulating layer that hold the second metal (bonding pad layer) to the underlying layer. ## Claims ### Claim 1 A method of forming an integrated circuit having an improved bonding pad which resists bonding pad peeling, the method comprising: providing a substrate having active or passive devices formed therein or thereon and having a substrate surface; forming a first metal layer over said substrate surface; masking and etching said first metal layer to form an array of anchor pads on said substrate surface in a bonding pad area; forming a first insulating layer over said substrate and said array of anchor pads, said anchor pads laterally separated from one another by said first insulating layer; forming via holes through said first insulating layer to expose surfaces of said anchor pads, said via holes having a smaller cross sectional area than said anchor pads; filling said via holes with a second metal layer and covering said first insulating layer in said bonding pad area with said second metal layer, said second metal layer making connections to said anchor pads through said via holes. ### Claim 2 (depends on 1) The method of claim 1 which further includes a metal contact to said second metal layer; and said metal contact is composed of a material selected from the group consisting of: aluminum and gold. ### Claim 3 (depends on 1) The method of claim 1 wherein said anchor pads have a square shape with a length and a width in the range between about 0.5 to 5.0 .mu.m. ### Claim 4 (depends on 1) The method of claim 1 wherein said via holes have a square shape with a length and width in the range between about 0.3 to 5.0 .mu.m. ### Claim 5 (depends on 1) The method of claim 1 where said anchor pads have a thickness in the range between about 1000 to 12,000 .ANG.. ### Claim 6 (depends on 1) The method claim 1 wherein said first insulating layer has a thickness in the range between about 3000 to 20,000 .ANG.. ### Claim 7 (depends on 1) The method claim 1 wherein said first insulating layer is formed of a material selected from the group consisting of silicon oxide, borophosphosilicate glass (BPSG), and phosphosilicate glass (PSG). ### Claim 8 (depends on 1) The method of claim 1 wherein said second metal layer is formed by forming a via metal layer filling said via holes, and forming a third metal layer overlying the via metal layer. ### Claim 9 (depends on 8) The method of claim 8 wherein said third metal layer has a thickness in the range between about 5000 to 20,000 .ANG.. ### Claim 10 (depends on 8) The method of claim 8 wherein said second metal layer has a thickness in the range between about 5000 .ANG. to 15,000 .ANG.. ### Claim 11 (depends on 1) The method of claim 1 which further includes forming a dielectric layer on the substrate surface, forming a titanium nitride layer on said dielectric layer and forming said second metal layer over said titanium nitride layer. ### Claim 12 (depends on 1) The method of claim 1 wherein said anchor pads are formed of a material selected from the group consisting of: aluminum, polycide, polysilicon, and a diffusion in said substrate. ### Claim 13 (depends on 1) The method of claim 1 wherein the spacing between adjacent metal pads is in the range between about 0.5 to 10 .mu.m. ### Claim 14 (depends on 1) The method of claim 1, wherein said via holes are centered on said anchor pads. ### Claim 15 A method for forming integrated circuit device including a bonding pad with an anchor structure, the method comprising: forming a conducting layer over a substrate; removing a portion of said conducting layer to form first and second individual anchor pads in the conducting layer; forming a first dielectric layer over and between said first and second individual anchor pads; forming a first via through said first dielectric layer and contacting said first individual anchor pad, said first via having a smaller cross-sectional area than said first individual anchor pad; forming a second via through said first dielectric layer and contacting said second individual anchor pad; said second via having a smaller cross-sectional area than said second individual anchor pad; and placing conducting material above said first dielectric layer and within said first and second vias to contact said first and second individual anchor pads, wherein a lower portion of said conducting material contacts said first and second individual anchor pads and an upper portion of said conducting material connects both said first and said second anchor pads to an external contact. ### Claim 16 (depends on 15) The method of claim 15, wherein said conducting material includes two metal layers. ### Claim 17 (depends on 15) The method of claim 15, wherein said vias and anchor pads are formed to be square in shape when viewed from above. ### Claim 18 (depends on 15) The method of claim 15, wherein said anchor pads are square in shape when viewed from perpendicular to said substrate. ### Claim 19 (depends on 15) The method of claim 15, wherein said vias and anchor pads are square in cross section. ### Claim 20 (depends on 15) The method of claim 15, wherein said first via contacts said first anchor pad in a center of said first anchor pad.