Influence of dielectric breakdown on MOSFET drain current

Breakdown of gate dielectric is one of the most dangerous threats for reliability of MOSFET devices in operating conditions. Not only the gate leakage resulting from breakdown is a problem for power consumption issues, but the "on" drain current can be strongly affected. In this paper, we show that in recent technologies, featuring ultrathin gate dielectrics, the corruption of drain current due to breakdown can be modeled as the effect of a portion of channel being damaged by the opening of the breakdown spot. Devices featuring 2.2- and 3.5-nm-thick gate oxide and various channel widths are stressed by using a specialized setup, and the degradation of transistor parameters is statistically studied. The analysis shows that the radius of the damaged region responsible for drain current degradation can be estimated between 1.4 and 1.8 /spl mu/m

RF-MEMS Switches Reliability for Long Term Spatial Applications

Ohmic RF-MEMS switches have been fully characterized regarding their robustness to Electro-Static Discharge events (ESD), Total Ionizing dose (TID) radiation, and long term actuation, obtaining important guidelines to improve the reliability of such devices. These tests, although very important for a complete device qualification for spatial applications, are in fact poorly investigated in literature

Dosimetry method for use in treatment of brain tumor, involves determining changes in threshold value of cells which are exposed to ionizing radiation by correlating address of cell to corresponding position in two-dimensional array

NOVELTY - The threshold value written cells of flash memory (12) are exposed to ionizing radiation and the state of the cells are read to calculate the absorbed dose. Address of each memory cell is correlated to corresponding position in a two-dimensional array and the changes in the threshold value of cells are determined. USE - Dosimetry method for use in treatment of brain tumor. Can also be used for security systems, sterilization application, high energy physics, space applications and medical applications. ADVANTAGE - Since changes in threshold value of cells which are exposed to ionizing radiation are determined by correlating address of each cell to corresponding position in two-dimensional array, ensures possibility of delivering very high dose to tumor without destroying the surrounding tissue. Thus the spatial resolution of the dosimeter is improved

Plasma induced damage from via etching in pMOSFETs

In this paper, we present a study of micro breakdown (MB), soft breakdown (SB), and conventional hard breakdown (HB) on pMOSFET devices. In particular, we report evident damage due to via etching

CELTIC-Cell Electroporation Technology Integrated Circuit"

Rapporto tecnico di progetto di ricerca (fine primo anno

Depassivation of Latent Plasma Damage in n-MOSFETs

Indispensable in CMOS manufacturing, plasma treatments may result in a latent damage in gate oxides. We propose a method to detect this latent damage as a function of the area of the multifingered metal pad connected to the gate, by using an experimental method based on constant current stress and oxide trapped charge measurements. We measured a power law behavior describing the dependence of the trapped charge on the injected charge

Destructive events in NAND Flash memories irradiated with heavy ions

Besides being widely used in virtually all terrestrial applications requiring non-volatile storage, Flash memories are arousing increasing interest with regards to space applications. This work presents new original data on the occurrence of destructive events and supply current spikes in NAND Flash memories exposed to heavy ions. Interestingly enough, these phenomena occur irradiating the devices even in stand-by mode. We examined the dependence of these effects on Linear Energy Transfer (LET) and flux of impinging ions, we used different test protocols, and shielded different blocks of the memory. Our analysis shows that the permanent loss of functionality occurs only with high-LET ions and usually with high particle flux, originating from damage to the charge pumps, likely due to Single Event Gate Rupture. We also show that there is not necessarily a correlation between irreversible damage and supply current spikes, as previously believed, even though they both originate in the charge pump circuitry

Radiation Sensitivity of Ohmic RF-MEMS Switches for Spatial Applications

The impact of 2 MeV protons and 10 keV X-rays radiation stresses on electrostatically actuated ohmic RF-MEMS switches has been analyzed at increasing radiation dose and during subsequent annealing at room temperature. Small variations of electrical parameters (actuation and release voltages) have been identified, accompanied by a strong rf-performances degradation. Monte Carlo TRIM simulations have been carried out to understand the mechanisms responsible of such degradations, finding that both NIEL and ionizing damages appear to play an important role