Semiconductor Manufacturing and Microtechnology Quiz

MEMS devices can act as sensors or actuators, translating physical changes to signals and vice versa.

Moore's Law states that the number of transistors on an integrated circuit doubles approximately every two years.

The process of manufacturing semiconductor devices includes various steps like design, wafer fabrication, front-end manufacturing, back-end manufacturing, packaging, and testing.

Front-end manufacturing encompasses all the steps involved in fabricating the integrated circuits on the wafer.

Back-end manufacturing involves packaging the device and testing its functionality.

The exposure step involves using a photomask with patterned chrome areas to expose the photoresist, creating a specific pattern on the wafer.

Photoresists are light-sensitive polymers that undergo chemical changes upon exposure to light, making them soluble or insoluble in developer solutions.

The exposure dose is the total amount of light energy received by the photoresist during exposure, determining the extent of the photochemical reaction.

Positive tone photoresist becomes soluble in the developer solution after exposure, allowing removal of the exposed areas, resulting in a positive image of the pattern on the mask.

Negative tone photoresist becomes insoluble in the developer solution after exposure, preserving the exposed areas and creating a negative image of the pattern on the mask.

Depth of focus represents the maximum thickness of the photoresist that can be exposed to achieve a vertical profile in the pattern.

Resolution refers to the minimum feature size that can be defined on the photoresist, determining the level of detail in the patterned feature.

Stepper is a type of photolithography system that transfers the mask pattern onto the wafer with multiple exposure steps, reducing the image size on the wafer to create the device layout.

A company that handles all stages of product development, production, and customer service, including design, manufacturing, and support.

A company that focuses solely on designing devices and providing customer service, but outsources the manufacturing process.

A company that specializes in manufacturing semiconductor devices, but does not design them.

A sensor that measures acceleration by detecting changes in capacitance due to the movement of a mass attached to a spring.

A device that measures angular rate (rotation) based on the Coriolis force acting on a vibrating mass.

A MEMS device that combines both an accelerometer and a gyroscope.

A manufacturing process used for micro-gyroscopes and accelerometers, involving two wafers: a sensor wafer for mechanical components and a cap wafer for sealing.

A sensor that measures pressure by detecting the deflection of a thin membrane, which acts as a capacitor in a Wheatstone bridge configuration.

A fabrication process used for pressure sensors, where a silicon membrane is suspended over pillars to create a sensitive area.

Controlled environments with extremely low levels of contaminants, used for manufacturing sensitive devices like MEMS.

A clean room designed with an open layout, allowing for flexibility in equipment placement.

A clean room design with a tunnel-like structure, ensuring a controlled air flow and reducing contamination risks.

The area within a clean room where the actual device manufacturing takes place, typically designated by white walls.

A system that circulates and filters air within a clean room to maintain its purity and prevent contamination.

The base material used in MEMS device manufacturing, requiring high purity and precision polishing.

A crystalline material used in semiconductor devices, chosen for its abundance, stability, and good mechanical and electrical properties.

The process of transferring a pattern onto a semiconductor wafer using light or other radiation to define the device structure.

The process of forming a layer of Silicon Dioxide (SiO2) on a silicon substrate by reacting it with oxygen or water vapor at high temperatures.

The native oxide layer naturally forms on silicon at room temperature, typically around 10 nanometers thick.

The process of thermal oxidation occurs at the interface between the silicon substrate and the growing oxide layer. The oxidizing species (oxygen or water) diffuse through the existing oxide to reach this interface where the reaction takes place.

Thermal oxidation can occur in either a dry environment (using pure oxygen gas) or a wet environment (using water vapor). Dry oxidation produces denser oxide, while wet oxidation is faster.

The Deal-Grove model predicts the growth rate of the oxide layer during thermal oxidation. It takes into account the temperature, time, and type of oxidation.

The oxidation rate slows down as the oxide layer thickens because the oxidizing species have a longer distance to travel to reach the silicon interface.

Temperature is the most important factor controlling the oxidation rate. Higher temperatures lead to faster oxidation rates.

A vertical furnace is used to perform thermal oxidation, capable of processing multiple wafers simultaneously. Gases are introduced from the top, and heating elements ensure uniform temperature distribution.

CVD (Chemical Vapor Deposition) is a process where gases are introduced into a chamber and react on the substrate surface to form a thin film. It's an alternative to thermal oxidation.

The boundary layer is the region near the wafer surface where reactant gases are transported via diffusion. This is crucial for surface reaction and film growth in CVD processes.

The process of using a liquid to clean the wafer surface, removing contaminants that could interfere with subsequent processing steps.

A type of wet cleaning process where the wafer is immersed in a liquid solution. This method is good for removing contaminants.

A wet cleaning technique where chemicals are sprayed onto a spinning wafer. This method is versatile and allows for more controlled cleaning.

A wet cleaning process that removes organic contaminants from the wafer surface. It's usually the first step in the cleaning sequence.

A wet cleaning process that removes metallic contaminants from the wafer surface. It's usually a later step in the cleaning sequence.

A wet etching process that removes material equally in all directions, creating rounded features, suitable for soft landings.

A wet etching process that removes material at different rates depending on the crystallographic orientation of the wafer, resulting in shaped features.

A method for creating patterned features by depositing material onto a substrate and then removing the undesired material using a lift-off process.

A bonding process used to permanently join two wafers together, typically using an intermediate layer, like glass frit.

A bonding method where a paste containing glass frit is used to bond two wafers together. The paste is heated to fuse the layers permanently.

A technique for applying glass frit paste to a wafer using a stencil and a squeegee. The paste is then heated to form a bonding layer.

A technique used to bond two wafers together permanently using a metal layer. The metal is etched to create specific patterns.

A bonding problem where moving parts in MEMS devices stick to stationary parts due to electrostatic forces, leading to device failure.

A process control technique used to assess the quality of a bond by measuring the force required to separate the bonded wafers.

A process control technique used to assess the quality of a bond by measuring the force required to pull the bonded wafers apart.

A deposition technique where a gaseous source material reacts at a high temperature (900-1200°C) to form a thin film on a substrate.

Epitaxial growth ensures precise doping levels, superior crystal quality compared to the substrate, and high purity with low oxygen content.

It's a variation of Vapor Phase Epitaxy where the substrate is monocrystalline silicon and leads to the growth of polycrystalline silicon on top. It results in a columnar structure with larger grain size and higher growth rate in comparison to LPCVD poly.

The walls of the quartz chamber used in Vapor Phase Epitaxy are transparent across a wide range of wavelengths to prevent excessive heating and material deposition.

The process allows for precise control of material properties by adjusting growth parameters like temperature and gas flow.

It's the use of Vapor Phase Epitaxy to produce sensor parts in gyroscopes (like free masses and springs) by growing thick (~30um) layers with specific residual stresses.

It's the process of creating cavities in semiconductors using epitaxially grown pillars followed by a process called H2 Annealing that removes the pillars and creates a cavity by migrating silicon atoms.

An isolation layer separates the substrate from other layers to prevent interaction and maintain desired functionality.

A method of depositing thin films at lower temperatures compared to thermal CVD, suitable for substrates with temperature constraints. It offers faster growth rates and better film quality.

A mixture of neutrals, positive ions, and electrons in a low-pressure gas environment generated by applying a potential difference between parallel plates.

A conductive medium found in PECVD where the upper electrode (showerhead) releases gases, and the bottom electrode (grounded) supports the wafer. The space between them is adjustable.

The area where the plasma is a good conductor, but the regions near the electrodes have limited conductivity. The voltage drop at the electrodes depends on the surface area of the electrodes.

The process of depositing a thin film uniformly on all surfaces of a device, including the vertical sides of steps. It's crucial for maintaining device functionality and ensuring uniformity.

The ratio of species that stick to a surface to the number of incident species, impacting the uniformity of the deposited film. Lower sticking coefficient leads to more conformal deposition.

Stress in a material that exists without any external forces applied, resulting from the deposition process and impacting the material's behavior.