RESUMO
We have used molecular beam epitaxy (MBE) based delta-doping technology to demonstrate nearly 100% internal quantum efficiency (QE) on silicon electron-multiplied charge-coupled devices (EMCCDs) for single photon counting detection applications. We used atomic layer deposition (ALD) for antireflection (AR) coatings and achieved atomic-scale control over the interfaces and thin film materials parameters. By combining the precision control of MBE and ALD, we have demonstrated more than 50% external QE in the far and near ultraviolet in megapixel arrays. We have demonstrated that other important device performance parameters such as dark current are unchanged after these processes. In this paper, we briefly review ultraviolet detection, report on these results, and briefly discuss the techniques and processes employed.
Assuntos
Dispositivos Ópticos , Teoria Quântica , Radiometria/instrumentação , Raios Ultravioleta , Elétrons , Desenho de Equipamento , Fótons , Silício/químicaRESUMO
Electronic detection of the binding event between biotinylated bovine serum albumen (BSA) and streptavidin is demonstrated with the chemoreceptive neuron MOS (CnuMOS) device. Differing from the ion-sensitive field-effect transistors (ISFET), CnuMOS, with the potential of the extended floating gate determined by both the sensing and control gates in a neuromorphic style, can provide protein detection without requiring analyte reference electrodes. In comparison with the microelectrode arrays, measurements are gathered through purely capacitive, non-Faradaic interactions across insulating interfaces. By using a (3-glycidoxypropyl)trimethoxysilane (3-GPS) self-assembled monolayer (SAM) as a simple covalent link for attaching proteins to a silicon dioxide sensing surface, a fully integrated, electrochemical detection platform is realized for protein interactions through monotone large-signal measurements or small-signal impedance spectroscopy. Calibration curves were created to coordinate the sensor response with ellipsometric measurements taken on witness samples. By monitoring the film thickness of streptavidin capture, a sensitivity of 25ng/cm2 or 2A of film thickness was demonstrated. With an improved noise floor the sensor can detect down to 2ng/(cm2mV) based on the calibration curve. AC measurements are shown to significantly reduce long-term sensor drift. Finally, a noise analysis of electrochemical data indicates 1/f(alpha) behavior with a noise floor beginning at approximately 1Hz.
Assuntos
Materiais Biomiméticos , Técnicas Biossensoriais/instrumentação , Técnicas Analíticas Microfluídicas/instrumentação , Redes Neurais de Computação , Mapeamento de Interação de Proteínas/instrumentação , Técnicas Biossensoriais/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Técnicas Analíticas Microfluídicas/métodos , Mapeamento de Interação de Proteínas/métodos , Reprodutibilidade dos Testes , Semicondutores , Sensibilidade e Especificidade , Integração de SistemasRESUMO
In this paper we present our system design and methodology for making absolute quantum efficiency (QE) measurements through the vacuum ultraviolet (VUV) and verify the system with delta-doped silicon CCDs. Delta-doped detectors provide an excellent platform to validate measurements through the VUV due to their enhanced UV response. The requirements for measuring QE through the VUV are more strenuous than measurements in the near UV and necessitate, among other things, the use of a vacuum monochromator, good dewar chamber vacuum to prevent on-chip condensation, and more stringent handling requirements.
RESUMO
Non-invasive, charge-based sensing in chemoreceptive neuron MOS (CvMOS) transistors with extended floating-gate structure has brought forth features that are beneficial to the system integration of biological sensing. This paper presents the results of fast electrolytic signal detection on silicon dioxide, which advances possible technologies for rapid DNA discrimination or external monitoring of cell action potentials.