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The reliability of ion-implanted power MESFETs submitted to RF and DC life-tests in impact ionization regime has been investigated by DC electrical characterization, LF noise analysis and Drain Current Transient analysis (DCTS). The two types of life-test have induced no degradation of the channel. RF life-test has induced DC parameter evolutions, but no significant drift of dynamic performances. Different evolutions of the interface state effective density in the gate-drain access region have been induced after DC and RF life-test.

The evaluation of the P-HEMT technology PH25 according to the European Space Agency requirements is presented. The reliability assessment plan features high temperature storage tests, DC life-tests and RF life-tests, performed on a set of evaluation test vehicles specifically defined for this purpose. The results of these tests evidence a temperature activated wear-out mechanism, a very low sensitivity of PH25 on strong RF stress and no sensitivity on hydrogen. Failure rates calculations are in line with the space programme requirements.

In this work we analyze degradation phenomena observed inpseudomorphic AlGaAs/InGaAs HEMTs with Al/Ti gate metallization, which have been submitted to accelerated tests at high drain-source voltage V Ds and high power dissipation P D . After these tests, we observe permanent degradation effects, consisting in electron trapping in the gate-drain access region, with consequent decrease in the longitudinal electric field and “breakdown walkout”, and in thermally-activated interdiffusion of the AI/Ti gate with decrease in the gate Schottky barrier height and increase in drain saturation current I D . Rather than causing a degradation of therf characteristics of the device, these phenomena induce an increase in the associatedrf gain at 12 GHz, the other rf characteristics being almost unchanged. Overall, the most relevant failure mode observed is an increase of low-frequency transconductance.

Presents a collection of slides covering the following topics: Q/V band - an ESA perspective; and ALPHASAT TDP5 mission. (58 pages)

This paper reports the design and implementation of a RF GaN Oscillator for test in space. This circuit/system will be applied in a space test of the European Space Agency and it will be one of the first experiments in space using European GaN devices. The main objective will be to study the material radiation hardness. In this paper we will present the proposed circuit for test and its main design procedure.

The purpose of this work is to evaluate the impact of RF life-test under gain compression on ion-implanted power MESFETs by LF gate noise and drain noise analysis combined with drain current transient spectroscopy (DCTS). While the devices under test belong to a mature technology, such an evaluation aims at reaching space program requirements in terms of reliability assessment.

Ion-implanted power MESFETs have been submitted to RF life-test under gain compression. Devices went through RF life-test with no significant dynamic performance drift but with DC parameter evolution. A complete electrical characterisation performed by low frequency gate and drain noise analysis combined with drain current transient spectroscopy revealed that no degradation has occurred in the channel. An increase by two orders of magnitude of the LF gate noise level points out a degradation located in the vicinity of the gate.

Eligibility criteria histologically proven OC, measurable/evaluable disease, relapse/progression after at least one platinum based CT, ≤ 3 prior CT. Treatment 1 or 2 prior CT, T = 175 mg/m2 [Group A (A) = 151 pts]; 3 prior CT, T = 135 mg/m2 [Group B (B) = 41 pts] both by 3 hour IV infusion q 3 w. pts(192): median (med) age: 57 yrs (25–72); PS 0 = 74 pts, PS 1 = 88 pts, PS 2 = 34 pts. nb prior CT: 1 = 81 pts, 2 = 73 pts, 3 = 36 pts. Toxicity (% cycles): 1184 evaluable cycles (cy) (983 in A, 201 in B) with a med nb per pt of 6 in A (1–21), 5 in B (1–11). Cardiac tox.: bradycardia: (≤ 60 bpm) always asymptomatic = 13% (63 pts), hypotension (≤ 90 mm/Hg) = 3% (24 pts), drop in systolic blood pressure 30 mm/Hg = 3% (23 pts). Out of 841 cy EKG 3% were abnormal (13 pts). Minor hypersensitivity reactions (HSR): 18% (A = 19%, B = 9%) in 73 pts, flushing (12%) and skin rash (4%). In 80 cy (7%) symptomatic treatment was required but never T discontinuation. No severe HSR occurred. Hematologic tox. induced treatment delay in 4% (A = 3%, B = 6%) and dose reduction in 1%. Gr 3–4 neutropenia: A = 32%; B = 22%. Eleven pts experienced in 18 cy. any degree off ever of infection associated with a Gr 4 neutropenia, all in A. Thrombocytopenia Gr 3–4 = 1% (10 cy). Anemia Gr 3–4 = 3%, Creatininemia Gr 3 = 1 pt. Liver Tox. = 11 pts (6 with liver metastasis): ALP Gr 3–4 = 1%; ASAT Gr 3 = 0.3%. Nausea/vomiting Gr 1–2 = 13%.; Gr 3 = 2 cy. Mucositis Gr 1–2 = 4% all in A. Paresthesias (present in 45 pts at inclusion) Gr 1–2: A = 43%, B = 28%, Gr 3: A = 5 cy. Myalgias/arthralgias Gr 1–2 =18% (A = 20%, B = 7%) and Gr 3 in 3 cy. Fatique Gr 1–2 = 26%. Edema Gr. 1–2 = 6% and Gr 3 in I cy. No toxic death occurred. Efficacy 185 evaluable pts, RR = 20% (CR = 5%, PR = 15%), SO = 32% (3 pts pCR) Conclusion Taxol® given by 3 H infusion, is well tolerated. The RR seems not different from those observed with 24 H infusion.

Le bombardement d'un cristal de Ni3Mn ordonne par les electrons du faisceau d'un microscope electronique 1,2 MV entraǐne une mise en desordre partielle de cet alliage. Le degre d'ordre ainsi obtenu depend de la direction d'irradiation. On donne une methode permettant de calculer le degre d'ordre pour n'importe queue direction d'irradiation; cette methode, utilisant la projection stereographique, tient compte de la focalisation des chocs le long des rangkes ⟨110⟩ du cristal. The bombardment of an ordered Ni3Mn crystal by the beam electrons of a 1,2 MV electron microscope involves this alloy in a partially disordered state. The degree of order thus obtained depends on the direction of irradiation We give a method allowing to calculate the degree of order for any direction of irradiation; this method, using the stereographic projection, takes into account the focalisstion of the collisions along the ⟨110⟩ atomic rows.

We have observed a gradual degradation of the output power not accompanied by drifts in the classical basic static parameters of a GaAs power MESFET. We report in the letter that this phenomenon can be explained by the development, during aging, of the gate-lag effect.