Semiconductor Processing Single Crystal Silicon

1
Semiconductor ProcessingSingle Crystal Silicon
Professor Masoud Agah ECE Department
2
Crystal Structure

• Solid ? in crystalline and amorphous forms
• Crystalline solids constituent atoms of the
  solid are spatially arranged in periodic fashion.
• Crystalline solid ? single crystal or
  polycrystalline
• Amorphous materials are devoid of long-range
  periodic structure.

3
Crystal Structure

• Lattice the periodic arrangement of atoms in a
  crystal
• Unit cell the smallest volume representing the
  lattice

Simple Cubic (SC) Body-Centered Cubic (BCC) Face-Centered Cubic (FCC)
4
Crystal Structure

• Directions are expressed similar to vectors in
  .
• In a cubic lattice, 100 010 001 ? lt100gt

5
Crystal Structure

• Deriving Miller indices to define a set of
  parallel planes
• The intercepts of the plane with the crystal axes
  are found.
• The reciprocal of the three integers are taken.
• The smallest set of integers h, k, and l are
  found that have the same relationship to each
  other as the three reciprocals (1/4, 1/3, and 1/2
  are converted to 3, 4, and 6). These integers are
  Miller indices of the plane, and the plane is
  labeled (h k l).
• Equivalent planes are labeled as h k l.
• In cubic cells, direction h k l is
  perpendicular to a plane (h k l).

6
Crystal Structure
7
Crystal Structure

• Silicon has a diamond cubic lattice.
• The diamond lattice also contains four lattice
  points per unit cell but contains 8 atoms per
  unit cell.
• The number of silicon atoms 5x1022 atoms/cm3

8
SCS Manufacturing
9
SCS Manufacturing