Electrical properties of doped silicon without P-N junction using micro-mesa shrinking patterns and differential Hall effect metrology

Abstract

Phosphorus (P) doped into n-type and p-type silicon (Si) yielded sample structures with and without a P-N junction. These samples were employed to evaluate electrical properties such as carrier dose, mobility, and sheet resistance using test patterns of various sizes for Differential Hall Effect Metrology (DHEM) measurements. Doped samples without P-N junctions provided inaccurate results compared to those with P-N junctions due to current leakage issues when standard mm-size patterns were used. The active ratio was found to be 57.4 % for samples with P-N junctions but it decreased significantly to 3.7 % for samples without the P-N junctions. Similarly, in DHEM depth profiles employing the standard size test pattern, the active ratio was 70.7 % for P-N junction samples and dropped to 3.7 % for those without. Using the micro-mesa shrinking test pattern, with mesa structures smaller than 25 μm in length, enabled accurate measurements of doped samples without P-N junctions. The electrical current depth was determined to be approximately 25–31 nm for P-doped n- and p-Si with a dose of ∼2E+15 atoms/cm² after RTA annealing. This study demonstrates that the combination of micro-mesa shrinking patterns and DHEM can reliably measure and evaluate the electrical properties of doped samples without P-N junctions.