摘要:
Methods and circuits for undiscoverable physical chip identification are disclosed. Embodiments of the present invention provide an intrinsic bit element that comprises two transistors. The two transistors form a pair in which one transistor has a wide variability in threshold voltage and the other transistor has a narrow variability in threshold voltage. The wide variability is achieved by making a transistor with a smaller width and length than the other transistor in the pair. The variation of the threshold voltage of the wide variability transistor means that in the case of copies of intrinsic bit elements being made, some of the “copied” wide variability transistors will have significantly different threshold voltages, causing some of the intrinsic bit elements of a copied chip to read differently than in the original chip from which they were copied.
摘要:
Methods and circuits for undiscoverable physical chip identification are disclosed. Embodiments of the present invention provide an intrinsic bit element that comprises two transistors. The two transistors form a pair in which one transistor has a wide variability in threshold voltage and the other transistor has a narrow variability in threshold voltage. The wide variability is achieved by making a transistor with a smaller width and length than the other transistor in the pair. The variation of the threshold voltage of the wide variability transistor means that in the case of copies of intrinsic bit elements being made, some of the “copied” wide variability transistors will have significantly different threshold voltages, causing some of the intrinsic bit elements of a copied chip to read differently than in the original chip from which they were copied.
摘要:
One of the wafers in a semiconductor wafer to wafer stack can be rotated a predefined number of positions, relative to a previous wafer in the stack, and bonded in the position in which the maximum number of good die are aligned. An adjustment circuit on each die reroutes signals received from a pad that has been relocated due to rotation. A communication channel formed from a pair of pads that are interconnected by a Through Substrate Vias can be placed in each die and can convey selected information from one die to the next. A code representative of the position orientation of each die can be recorded in a Programmable Read Only Memory located on each die, or may be down loaded from a remote source. Any additional wafer may be stacked serially, and each one may be rotated relative to the wafer that precedes it in the stack.
摘要:
One of the wafers in a semiconductor wafer to wafer stack can be rotated a predefined number of positions, relative to a previous wafer in the stack, and bonded in the position in which the maximum number of good die are aligned. An adjustment circuit on each die reroutes signals received from a pad that has been relocated due to rotation. A communication channel formed from a pair of pads that are interconnected by a Through Substrate Vias can be placed in each die and can convey selected information from one die to the next. A code representative of the position orientation of each die can be recorded in a Programmable Read Only Memory located on each die, or may be down loaded from a remote source. Any additional wafer may be stacked serially, and each one may be rotated relative to the wafer that precedes it in the stack.