In solid-state electronics, silicon atoms arrange themselves in an orderly, repeating three-dimensional pattern. What is this long-range atomic arrangement called in materials science and semiconductor fabrication?

Introduction / Context:
Understanding how atoms are arranged inside a material is fundamental to electronics. Silicon, the workhorse of integrated circuits, does not exist as isolated atoms inside a chip; instead, it forms a repeating three-dimensional network. The question asks for the correct term used in materials science and semiconductor fabrication for this long-range, ordered structure.

Given Data / Assumptions:

• The material under discussion is elemental silicon used in wafers and devices.
• Atoms are arranged in a regular, repeating pattern through the bulk of the solid.
• We are looking for the correct term for the macroscopic orderly arrangement.

Concept / Approach:
When atoms occupy periodic positions in space, the solid is said to be crystalline. Silicon specifically forms a diamond-cubic crystal structure held together by covalent bonds. While “covalent bond” names the type of bonding between neighboring atoms, and “semiconductor” names the electrical classification, the question asks for the structural arrangement itself, which is a crystal. “Valence orbit” refers to electron shells, not lattice arrangement.

Step-by-Step Solution:

Verification / Alternative check:
X-ray diffraction patterns from silicon show sharp Bragg peaks, a signature of crystalline order. Amorphous or polycrystalline materials would produce broadened peaks or multiple grain orientations, not the single-crystal pattern typical of wafer-grade silicon.

Why Other Options Are Wrong:

Common Pitfalls:
Confusing bonding (covalent) with structure (crystal), or material class (semiconductor) with atomic arrangement. Always separate bonding type, electrical behavior, and lattice structure when classifying materials.

Final Answer:
Crystal