Process materials (gases and chemicals)
Learn the basics of process materials — specialty gases, ultrapure water, etching gases, sputtering targets and high-purity silicon — through multiple-choice questions.
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Process materials (gases and chemicals): key points
Semiconductor manufacturing uses many materials: high-purity silicon, specialty gases for deposition and etching, chemicals and ultrapure water for cleaning, sputtering targets, photoresists, CMP slurries and more.
Even tiny amounts of impurities can cause defects, so these materials must be extremely pure. Many of the gases are also pyrophoric or toxic, so safe handling is essential.
All Process materials (gases and chemicals) questions (50)
- What is the main hazard in handling silane (SiH4), used as a source for CVD and other processes?
- What is the most appropriate approximate purity required of polycrystalline silicon (polysilicon) feedstock for semiconductors?
- Which is a typical indicator used to control the purity of ultrapure water in semiconductor manufacturing?
- Which gases are mainly used for dry etching of silicon oxide (SiO2)?
- Which correctly describes the target used in sputtering?
- Which combination correctly lists the main components of chemically amplified photoresist?
- Which correctly describes phosphine (PH3) and arsine (AsH3), used to introduce n-type dopants?
- What is the main use of nitrogen trifluoride (NF3)?
- Which units are commonly used to express impurity concentrations in high-purity semiconductor gases and chemicals?
- Which material is commonly used for CMP polishing pads?
- Which source gases are used to introduce the p-type dopant boron?
- Which devices are installed in piping to remove trace impurities and particles from gases just before they are supplied to equipment?
- Which combination of gases is used to make an ArF excimer laser oscillate?
- Which gas is used as a carrier gas and reducing atmosphere in epitaxial growth and heat treatment?
- What must be watched for when handling metal-organic compounds such as trimethylgallium (TMGa), used as MOCVD sources?
- What purity does '6N' denote for a gas?
- Which gas, one of the most heavily used in semiconductor fabs, is supplied by pipeline for purging and as an atmosphere gas?
- In ArF immersion lithography, which film is applied over the photoresist to keep the immersion water from contacting it directly?
- Which is a typical material used for low-k interlayer dielectrics?
- Which high-purity, heat-resistant material is widely used for the process tubes of furnaces and the fixtures that hold wafers?
- Which aqueous solution is commonly used to develop photoresist?
- What is the main reason organic alkalis such as TMAH, rather than sodium hydroxide, are used as semiconductor developers?
- Which correctly describes chlorine trifluoride (ClF3), used for chamber cleaning and similar purposes?
- What is the main composition of the plating bath used to electroplate copper wiring?
- Which correctly describes a risk related to the supply of semiconductor materials?
- Which material is used for the substrates of photomasks for ArF exposure?
- Which combination of materials is used in the reflective multilayer of EUV masks?
- In oxide etching, why are carbon-rich fluorocarbon gases such as C4F8 used?
- What purity is typically required for copper sputtering targets used for seed layers?
- What is the chemical name of IPA, used for drying after cleaning and similar purposes?
- Which set correctly lists the main kinds of process materials used in semiconductor manufacturing?
- What is the appropriate general way to store photoresist?
- For what purpose is ultrapure water used in the largest quantities in semiconductor fabs?
- What is the main reason extremely high purity is required of the gases and chemicals used in semiconductor manufacturing?
- Which combination of material and surface treatment is commonly used for high-purity gas piping?
- Which device in deposition and etch tools precisely measures gas flow and controls it to stay constant?
- What is the main composition of positive resists widely used for g-line and i-line exposure?
- Which material is widely used for piping and containers of highly corrosive chemicals such as hydrofluoric acid?
- What is the typical method for producing, near the fab, the large volumes of nitrogen gas used in semiconductor plants?
- Which source gas can deposit silicon films at lower temperatures than monosilane (SiH4)?
- Which gas is used as the germanium source in SiGe epitaxial growth?
- Which gas is sometimes used as the oxidant with silane to deposit silicon oxide or oxynitride films by CVD?
- Why are dopant gases such as diborane and phosphine often supplied diluted to low concentrations in hydrogen, nitrogen or similar?
- Which measure is commonly used to express trace moisture in high-purity gases?
- How are sources that are liquid at room temperature (such as TEOS) supplied as gas to CVD tools?
- Which type of fitting, widely used in high-purity gas piping, seals by compressing a metal gasket between faces?
- What degradation tends to occur when quartz parts in heat-treatment furnaces are used at high temperature for a long time?
- Why must gas piping be designed to minimize dead spaces, the stagnant pockets where gas does not flow?
- What is the operation called in which a gas line is repeatedly pressurized with inert gas and evacuated before it is opened or switched to another gas?
- Why is moisture in halogen-based gases such as hydrogen chloride controlled especially strictly in gas piping?