459 results about "Circuit reliability" patented technology

The present invention is directed to a number of improvements in methods for reliability simulations in aged circuits whose operation has been degraded through hot-carrier or other effects. A plurality of different circuit stress times can be simulated within a single run. Different aging criteria may be used for different circuit blocks, circuit block types, devices, device models and device types. The user may specify the degradation of selected circuit blocks, circuit block types, devices, device models and device types independently of the simulation. Device degradation can be characterized in tables. Continuous degradation levels can be quantized. Techniques are also described for representing the aged device in the netlist as the fresh device augmented with a plurality of independent current sources connected between its terminals to mimic the effects of aging in the device. The use of device model cards with age parameters is also described. To further improve the circuit reliability simulation, a gradual or multi-step aging is used instead of the standard one step aging process. Many of these features can be embedded within the circuit simulator. A user data interface is also presented to implement these techniques and further allow users to enter their device models not presented in the simulator. For example, a proprietary model of, say, the substrate current in an NMOS could used be with a SPICE simulator employing a different model to simulate the aging of the circuit.

The invention belongs to the technical field of integrated circuit test, and in particular relates to a circuit and a method for testing reliability of an integrated circuit. According to the core circuit of the testing circuit, auxiliary p-type metal oxide semiconductor field effect transistors (pMOSFETs) and n-type metal oxide semiconductor field effect transistors (nMOSFETs) are connected between every two stages of inverters of a ring oscillator (RO) and between a high level Vdd and low potential Vss, and a switch transistor is plugged in an input and output connecting line. By controlling the grid voltages of the auxiliary transistors and the switch transistor, normal oscillation of the RO can be realized in the core circuit, dynamic stress is applied to complementary metal oxide semiconductor field effect transistors (CMOSFETs) of the RO, and negative bias temperature instability (NBTI), positive bias temperature instability (PBTI) and hot carrier injection (HCI) stresses are respectively applied to the pMOSFETs or the nMOSFETs of the RO. The testing circuit has the functions of: degradation measurement of the pMOSFETs in the RO under the NBTI stress, degradation measurement of the nMOSFETs under the PBTI stress, degradation measurement of the pMOSFETs under the HCI stress, degradation measurement of the nMOSFETs under the HCI stress, and comparison with degradation measurement of the CMOSFETs under the dynamic stress.