# US 6,297,536 B2 · Diode structure compatible with silicide processes for ESD protection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,297,536 B2 - Document ID: US6297536B2 - Status: Granted - Kind: B2 - Application number: 09/270,830 - Filed: 1999-03-18 - Published: 2001-08-16 - Granted: 2001-10-02 - Earliest claimed: 1998-11-30 - Assignees: Winbond Electronics Corp. - Inventors: Ta-Lee Yu - Web page: https://patentgrep.com/patent/US6297536B2 ## CPC - H10D 84/221: {of only diodes} - H10D 8/411: {PN diodes having planar bodies} - H10D 89/611: {using diodes as protective elements} - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES ## Abstract A diode structure compatible with silicide processes for electrostatic discharge protection is disclosed. The diode structure comprises a semiconductor layer of a first conductivity type, a diffusion region of a second conductivity type formed in the semiconductor layer, and a doped region of the second conductivity type formed in the semiconductor layer around the diffusion region. The doped region has a doping concentration less than that of the diffusion region to provide a ballastic resistance under a high current stressing condition. ## Claims ### Claim 1 A diode structure for electrostatic discharge protection, comprising: a semiconductor layer of a first conductivity type, directly coupled to a first pad; a diffusion region of a second conductivity type formed in said semiconductor layer, directly coupled to a second pad; a silicide layer overlying said diffusion region; and a doped region of the second conductivity type formed in said semiconductor layer around the edge of said diffusion region, wherein said doped region has a doping concentration less than that of said diffusion region to provide a ballastic resistance between the first pad and the second pad under a high current stressing condition. ### Claim 2 (depends on 1) The diode structure as claimed in claim 1, further comprising a gate ring formed on said semiconductor layer around said diffusion region. ### Claim 3 (depends on 2) The diode structure as claimed in claim 2, further comprising a spacer formed on the inner sidewall of said gate ring. ### Claim 4 (depends on 3) The diode structure as claimed in claim 3, wherein said doped region has a junction depth less than that of said diffusion region. ### Claim 5 (depends on 1) The diode structure as claimed in claim 1, wherein said doped region is a well region. ### Claim 6 (depends on 5) The diode structure as claimed in claim 5, wherein said doped region has a junction depth greater than that of said diffusion region. ### Claim 7 (depends on 1) The diode structure as claimed in claim 1, wherein the first conductivity type is P-type and the second conductivity type is N-type. ### Claim 8 (depends on 1) The diode structure as claimed in claim 1, wherein the first conductivity type is N-type and the second conductivity type is P-type. ### Claim 9 (depends on 1) The diode structure as claimed in claim 1, wherein the diffusion region is encircled by a field oxide ring. ### Claim 10 A diode structure for electrostatic discharge protection, comprising: a semiconductor layer of a first conductivity type; a diffusion region of a second conductivity type formed in said semiconductor layer and directly coupled to a first pad; a silicide layer overlying said diffusion region; a gate ring formed on said semiconductor layer around said diffusion region and directly coupled to a second pad; and a doped region of the second conductivity type formed in said semiconductor layer around the edge of said diffusion region, wherein said doped region has a doping concentration less than that of said diffusion region to provide a ballastic resistance between the first pad and the second pad under a high current stressing condition. ### Claim 11 (depends on 10) The diode structure as claimed in claim 10, further comprising a spacer formed on the inner sidewall of said gate ring. ### Claim 12 (depends on 11) The diode structure as claimed in claim 11, wherein said doped region has a junction depth less than that of said diffusion region. ### Claim 13 (depends on 10) The diode structure as claimed in claim 10, wherein the first conductivity type is P-type and the second conductivity type is N-type. ### Claim 14 (depends on 10) The diode structure as claimed in claim 10, wherein the first conductivity type is N-type and the second conductivity type is P-type. ### Claim 15 A diode structure for electrostatic discharge protection, comprising: a semiconductor layer of a first conductivity type; a diffusion region of a second conductivity type formed in said semiconductor layer; a silicide layer overlying said diffusion region; and a well region of the second conductivity type formed in said semiconductor layer around the edge of said diffusion region, wherein said well region has a doping concentration less than that of said diffusion region to provide a ballastic resistance under a high current stressing condition. ### Claim 16 (depends on 15) The diode structure as claimed in claim 15, wherein said well region has a junction depth greater than that of said diffusion region. ### Claim 17 (depends on 15) The diode structure as claimed in claim 15, wherein the first conductivity type is P-type and the second conductivity type is N-type. ### Claim 18 (depends on 15) The diode structure as claimed in claim 15, wherein the first conductivity type is N-type and the second conductivity type is P-type. ### Claim 19 (depends on 15) The diode structure as claimed in claim 15, further comprising a field oxide ring formed on said semiconductor layer around said diffusion region.