摘要:
Provided herein are methods and devices for measuring pH and for amplifying a pH signal to obtain ultrasensitive detection of changes in pH. This is achieved by providing a sensor and a transducer, wherein the sensor transconductance is sensitive to changes in pH and the transducer transconductance is not affected by pH change. The transducer instead compensates for changes in the sensor transconductance arising from pH change. The unique configuration of the sensor and transducer with respect to each other provides substantial increases in a pH amplification factor, thereby providing pH sensing devices with a giant Nernst response and, therefore, effectively increased pH sensitivity.
摘要:
In one aspect, described herein are field effect chemical sensor devices useful for chemical and/or biochemical sensing. Also provided herein are methods for single molecule detection. In another aspect, described herein are methods useful for amplification of target molecules by PCR.
摘要:
Provided are semiconductor field effect sensors including a high-k thin film gate dielectric. The semiconductor field effect sensors described herein exhibit high detection sensitivity and enhanced reliability when placed in contact with liquids. Also disclosed are semiconductor field effect sensors having optimized fluid gate electrode voltages and/or back gate electrode voltages for improved detection sensitivity.
摘要:
In one aspect, described herein are field effect chemical sensor devices useful for chemical and/or biochemical sensing. Also provided herein are methods for single molecule detection. In another aspect, described herein are methods useful for amplification of target molecules by PCR.
摘要:
Apparatus and methods for detecting molecules in a fluidic environment are provided, including nanodevices and methods for fabricating, functionalizing, and operating such nanodevices. At least one of the methods includes selective heating of nanodevices in an array.
摘要:
Walkout in high voltage trench isolated semiconductor devices is inhibited by applying a voltage bias signal directly to epitaxial silicon surrounding the device. Voltage applied to the surrounding epitaxial silicon elevates the initial breakdown voltage of the device and eliminates walkout. This is because voltage applied to the surrounding epitaxial silicon reduces the strength of the electric field between the silicon of the device and the surrounding silicon. Specifically, application of a positive voltage bias signal to surrounding epitaxial silicon equal to or more positive than the most positive potential occurring at the collector during normal operation of the device ensures that no walkout will occur.
摘要:
Process for the formation of epitaxial layers with controlled n-type dopant concentration depth profiles for use in NPN bipolar transistors. The process includes first providing a semiconductor substrate (e.g. a [100]-oriented silicon wafer substrate) with an n-type collector precursor region formed on its surface, followed by forming an n-type (e.g. phosphorous or arsenic) in-situ doped epitaxial layer of a thickness t1 on the n-type collector precursor region. Next, an undoped epitaxial layer of a thickness t2 is formed on the n-type in-situ doped epitaxial layer. A p-type (e.g. boron) in-situ doped epitaxial base layer is subsequently formed on the undoped epitaxial layer. The process can also include the sequential formation of an undoped Si1−xGex epitaxial layer and a p-type in-situ doped Si1−xGex epitaxial layer between the undoped epitaxial layer and the p-type in-situ doped epitaxial base layer. Accumulation of the n-type dopant concentration in p-type epitaxial layers (such as the p-type in-situ doped epitaxial base layer or the p-type in-situ doped Si1−xGex epitaxial layer) that are formed subsequent to a non-p-type epitaxial layer (such as the undoped epitaxial layer or undoped Si1−xGex epitaxial layer, respectively) is controlled by manipulating the thickness ratio of t2 to t1, while keeping the thickness of N-layer fixed at t (i.e. t1+t2).
摘要:
A method of manufacturing truly complementary bipolar transistors on a common substrate. The method results in the fabrication of vertical NPN and PNP transistors which have an identical structure and mode of operation, with both devices operating in the downward direction. The inventive method permits independent control of the characteristics of the two devices, producing a closely matched performance for both devices.
摘要:
A semiconductor device, polysilicon-contacted trench isolation- structure that provides improved electrical isolation stability, a method of operating a polysilicon-contacted trench isolated semiconductor device, and a process for manufacturing a polysilicon-contacted trench isolation structure. The trench isolation structure includes an isolation trench formed in a semiconductor substrate. The isolation trench has a layer of trench lining oxide, a layer of trench lining silicon nitride and a trench fill polysilicon (poly 1) layer. Exposed lateral surfaces of the poly 1, which extend above the trench lining silicon nitride, are contacted to another layer of polysilicon (poly 2). The method of operation includes applying a bias voltage to the trench fill poly 1 layer via poly 2. The process for manufacture includes etching an isolation trench that extends through a layer of field oxide and into a semiconductor substrate. After forming layers of trench lining oxide, trench lining silicon nitride and trench fill poly 1 in the isolation trench, the trench lining silicon nitride is etched back to expose lateral surfaces of the trench fill poly 1. A poly 2 layer is then deposited and makes contact with the exposed lateral surfaces of the trench fill poly 1.
摘要:
A process for anisotropically etching a tungsten silicide or tungsten polycide structure. If the silicide/polycide film has an overlying oxide layer, the insulating layer is removed by a gas mixture composed of CHF.sub.3 and C.sub.2 F.sub.6. The WSi.sub.x silicide layer is then etched in a reactive ion etch using a gas mixture formed from Cl.sub.2 and C.sub.2 F.sub.6, with sufficient O.sub.2 added to control polymer formation and prevent undercutting of the silicide. The polysilicon layer is then etched using a gas mixture formed from Cl.sub.2 and C.sub.2 F.sub.6. The result is a highly anisotropic etch process which preserves the critical dimension of the etched structures. The etch parameters may be varied to produce a tapered sidewall profile for use in the formation of butted contacts without the need for a contact mask.
摘要翻译:用于各向异性蚀刻硅化钨或聚钨酸钨结构的方法。 如果硅化物/多硅化物膜具有上覆氧化物层,则通过由CHF 3和C 2 F 6组成的气体混合物除去绝缘层。 然后使用由Cl 2和C 2 F 6形成的气体混合物在反应离子蚀刻中对WSix硅化物层进行蚀刻,加入足够的O 2以控制聚合物形成并防止硅化物的底切。 然后使用由Cl 2和C 2 F 6形成的气体混合物来蚀刻多晶硅层。 结果是高度各向异性的蚀刻工艺,其保留蚀刻结构的临界尺寸。 可以改变蚀刻参数以产生用于形成对接触点的锥形侧壁轮廓,而不需要接触掩模。