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**Anti-Fuse and eFuse Process Integration for One-Time Programmable Memory** is **the integration of one-time programmable (OTP) memory using anti-fuse or electrically-programmable fuse structures — enabling secure code storage and post-manufacturing configuration**. Anti-Fuses and Electrically-Programmable Fuses (eFuses) provide one-time programmable (OTP) memory — information is programmed once and cannot be erased. OTP is valuable for security-critical information, device identification, wafer-level serialization, and trimming calibration values. OTP provides non-volatility without periodic refresh needed by DRAM and simpler than flash. Anti-Fuse (eFuse) Process: Anti-fuses are normally high-resistance structures that become conductive after programming. eFuse is the electronic variant implemented in CMOS. Polysilicon eFuses are created by passing high current through polysilicon resistors, melting and creating conductive path. Metal eFuses are high-resistance metal structures programming similarly. Programmable metal eFuses in advanced nodes offer lower resistance and smaller area than polysilicon. Forward diode eFuses use current injection through reverse-biased junction, creating damage and conductive path. Anti-fuse programming requires high current and voltage. Specialized charge pump circuits generate programming voltage (5-12V typical). Current mirrors set programming current. Programming duration (pulse) is controlled — brief pulse melts fuse; extended pulse increases conductivity. Each eFuse requires individual programming address and current path. Large eFuse arrays require sophisticated current distribution and address decoding. Resistance shift after programming varies — some designs accept high post-programming resistance (megaohms), others (like data eFuses) require lower resistance (ohms to tens of ohms). Trimming eFuses program to correct calibration values — oscillator frequency, threshold voltages, analog bias. Functional requirements (resolution, accuracy) drive trimming architecture. Security eFuses store encryption keys and security policy. Access control and secure boot code prevent unauthorized modification. Authentication codes verify eFuse integrity. Reliability of eFuse structures requires extensive testing. Temperature cycling affects resistance. Electromigration from high programming current can degrade long-term reliability. **Anti-Fuse and eFuse enable cost-effective one-time programming for configuration, security, and trimming, with specialized process integration and careful programming control.**