Discussion
The chemical used for shielding the active areas to achieve selective oxide growth is :
Answer: B
The masking chemical is silicon nitride.
In the LOCOS (local oxidation of silicon) process, a patterned layer of silicon nitride, Si3N4, covers the active areas where transistors will be built. Oxygen and water vapour diffuse through nitride extremely slowly, so the field oxide grows only in the exposed regions, isolating neighbouring devices.
Silver nitride is not used in silicon processing. Hydrofluoric acid etches silicon dioxide; it removes oxide rather than masking against its growth. Polysilicon is used for gates and as a buffer layer in some LOCOS variants, but it oxidises readily and is not the mask itself.
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development