Physical fuse for semiconductor integrated circuit
AssigneeSGS-Thomson Microelectronics S.A.
InventorsRichard Pierre Fournel, Serge Fruhauf, Fran.cedilla.ois Tailliet
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Abstract
A fuse for an integrated circuit is constituted by a shallow NP junction, covered with a metal contact, the semiconductor region being not excessively doped. For the blowing of the fuse, the junction is forward biased with a current sufficient to enable a diffusion of metal up to the junction. This short-circuits the junction. The detection is done also by the forward biasing of the junction, but with a low current or a low voltage. The detection can also be done with reverse biasing.
Claims24
A physical fuse circuit with a low blow-out voltage and a low blow-out current density for integrated circuits formed in a semiconductor substrate, including a circuit for blowing the fuse, comprising:
- a shallow, doped first semiconductor region having a first conductivity type, diffused in a second semiconductor region having a second conductivity type that is opposite to the first conductivity type;
- and
- a diffusion metal layer formed in direct contact with the doped first semiconductor region;
- wherein
- the first semiconductor region has a depth of about 0.2 microns, and a voltage of about 3-5 Volts across the fuse produces a blow-out current with a current density substantially one milliampere per square micrometer at the diffusion metal layer.
A physical fuse with a low blow-out voltage of about 3-5 Volts and a low blow-out current density of substantially one miliampere per square micrometer, formed in semiconductor substrate of an integrated circuit, comprising:
- a junction formed of a shallow region of a depth of about 0.2 microns and of a first conductivity type in contact with a region of a second conductivity type;
- and
- a diffusion metal layer disposed in direct contact with the shallow region, the metal selected to diffuse readily through the shallow region when a blow-out current passes through the metal.
Dependencies are inferred from the claim text.