Effects of photoresist polymer molecular weight on line-edge roughness and its metrology probed with Monte Carlo simulations
A fast 2D/3D resist dissolution algorithm based on the critical ionization model is used to quantify line-edge roughness and determine its relation to resist polymer molecular weight, the end-to-end distance and the radius of gyration, keeping acid effects off (i.e., minimal). The algorithm permits also simulations of line-edge roughness metrology by examining the effects of SEM measurement box length.
Monte Carlo simulation of gel formation and surface and line-edge roughness in negative tone chemically amplified resists
A molecular-based representation of a negative tone chemically amplified resist was developed and studied using stochastic simulations. The gel formation mechanism resulting from the reaction–diffusion phenomena in the polymer matrix during the postexposure bake step, as well as the surface and line-edge roughness formation were investigated in two dimensions. Graph theory computational techniques were employed to determine the gel cluster size and its relation to the fraction of the total number of chemically and physically cross-linked chains. Results of the simulation include the maximum acid diffusion range, the cross-link density, the surface and line edge roughness, versus exposure dose and photoacid generator concentration.
The role of prolactin in andrology: what is new?
Prolactin (PRL) has been long deemed as a hormone involved only in female reproduction. However, PRL is a surprising hormone and, since its identification in the 1970s, its attributed functions have greatly increased. However, its specific role in male health is still widely unknown. Recently, low PRL has been associated with reduced ejaculate and seminal vesicle volume in infertile subjects. In addition, in men consulting for sexual dysfunction, hypoprolactinemia has been associated with erectile dysfunction and premature ejaculation, findings further confirmed in the general European population and infertile men. Several metabolic derangements, recapitulating metabolic syndrome, have also been associated with low PRL both in men with sexual dysfunction and from the general European population. In men with sexual dysfunction, followed-up for more than 4 years, low PRL was identified as an independent predictor of the incidence of major adverse cardiovascular events. Finally, an association with anxiety or depressive symptoms has been found in men with sexual dysfunction and from the general European population. While a direct role for impaired PRL function in the pathogenesis of these reproductive, sexual, metabolic and psychological disorders is conceivable, the possibility that low PRL is a mirror of an increased dopaminergic or a decreased serotonergic tone cannot be ruled-out. Hyperactivity of the dopaminergic system can explain only a few of the aforementioned findings, whereas a hypo-serotonergic tone fits well with the clinical features associated with low PRL, and there is significant evidence supporting the hypothesis that PRL could be a mirror of serotonin in the brain.