Electronic Grade Sulfuric Acid Procurement Guide 2026: SEMI C36 Grades, Purity Specs and Wafer-Fab Supplier Selection

1. Overview

Electronic Grade Sulfuric Acid (EGS) is among the highest-volume wet electronic chemicals used in semiconductor manufacturing, primarily for wafer cleaning, post-etch removal and RCA cleaning at 300 mm fabs. Unlike technical-grade sulfuric acid, EGS is controlled to ppb-level limits for metallic impurities, particles and anions.

2. Core Applications

• SPM cleaning (sulfuric acid–hydrogen peroxide mix): removes photoresist residues and organic contamination, a critical step in advanced nodes.
• RCA standard cleaning: paired in SC-1/SC-2 sequences to remove particles and metallic contamination.
• Post-etch treatment: clears etch byproducts to protect interface cleanliness.

3. Key Specifications & SEMI Grades

Purity is typically graded per SEMI C36 and the “Grade” system (UP / UP-S / UP-SS / UP-T):

• Metallic impurities: individual metals (Na, K, Fe, Cu, Zn, Cr, etc.) typically controlled below 1 ppb; higher grades (UP-SS/UP-T) demand even lower.
• Particle control: ≥0.5 μm particles per mL must meet fab acceptance limits.
• Concentration & consistency: commonly 96%–98%, with minimal batch-to-batch variation in metal content.

4. Procurement Essentials

• Supplier qualification: prioritize vendors with SEMI C36 compliance, fab qualification history and stable lot data.
• Localization assessment: the high-purity sulfuric acid localization gap remains large with few qualified suppliers; adopt a three-stage path of sample assay, pilot and line validation before mass adoption.
• Packaging & logistics: use HDPE drums or dedicated tank trucks to prevent metal and particle contamination.
• Quality documentation: every lot should ship with a COA and metal/particle test reports.

5. Selection Checklist

1. Define target process (SPM / RCA / post-etch) and required grade (UP / UP-S / UP-SS / UP-T).
2. Request the last three lots’ COAs; verify individual metals ≤1 ppb and particle specs.
3. Confirm the supplier has fab or panel qualification references.
4. Evaluate pilot and line-validation lead time for localization candidates.

6. Summary

EGS is a priority category for wet electronic chemical localization. Procurement should center on purity grade, batch stability and supplier qualification, while leveraging localization trends to optimize cost and supply security.