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primarysourced Photonics sector Tower
TSEM
~2 min read · 476 words ·updated 2026-04-29

Tower Semiconductor (NASDAQ: TSEM)

Tower Semiconductor Ltd. is an Israeli specialty-analog wafer foundry headquartered in Migdal Haemek. Public on NASDAQ since 1994 (TSEM, CIK 0000928876). Foreign Private Issuer filing Form 20-F annually + 6-K for interim disclosure.

For the photonics-research scope, the load-bearing assets are:

  1. PH18 silicon-photonics process — 200mm SiPh on the Newport Beach Fab 3 (legacy Jazz Semiconductor 8-inch SiGe BiCMOS line, acquired in the May 2008 Tower-Jazz stock-for-stock merger). Carrier for Lightwave Logic’s electro-optic polymer under the formal development agreement signed March 11, 2026. Sits opposite GlobalFoundries Fotonix (300mm 45SPCLO + 9WG) in the AI-photonics foundry-tier duopoly.
  2. Tower-ST Agrate 300mm joint — capacity-extension partnership with STMicroelectronics on a 300mm RF/analog node in Italy (announced June 24, 2021; first 65nm BCD platform productized December 23, 2024).
  3. TPSCo (Tower Partners Semiconductor Co.) — Japan-fab joint with Nuvoton (formerly Panasonic Semi) covering Uozu + Arai 200mm/300mm; ownership flipped to Nuvoton 2020.
  4. Tower-Intel Foundry Services agreement (Sep 5, 2023) — $300M Tower equipment investment in Intel’s Fab 11X (Rio Rancho, NM) opening 600,000+ photo-layer-per-month 300mm corridor for Tower’s specialty processes. (Note: this is a capacity-services arrangement, not a Tower fab acquisition.)

This site refreshes daily — price (NASDAQ close), short interest, EDGAR filings, Form 4 insider transactions (post-2026-03-18 HFIAA only), and Schedule 13G/13F institutional-holder updates.

Filing-regime context: TSEM is an Israeli-incorporated Foreign Private Issuer (FPI) filing Form 20-F (annual) + 6-K (interim) under SEC Exchange Act §12 — same regime as POET and GFS, NOT 10-K/10-Q. Section 16 / Form 4 insider reporting was historically FPI-exempt but applies to TSEM officers/directors on or after 2026-03-18 under the HFIAA (Holding Foreign Issuers Accountable Act, signed 2025-12-18, effective 2026-03-18) which repealed the FPI Section 16(a) carve-out.

Scope note: This KB is intentionally narrowed to the foundry layer of the AI-photonics value chain — PH18 process, the LWLG development agreement, customer wins, and the financial structure underlying that capacity. The diversified Tower business (RF mobile, power management, automotive analog, image sensors, MEMS) is covered as cross-context, not as the primary thesis subject.

Recent corporate-history context: The Aug 2023 collapse of the $5.4B Intel acquisition (announced Feb 2022; abandoned over China antitrust clearance) recast Tower as a standalone listed FPI rather than an Intel-internal foundry asset. The settlement included a $353M reverse-termination fee paid by Intel to Tower.

Sections

  • Company — corporate history, leadership, governance, Intel-deal collapse, M&A
  • Technology — PH18 SiPh, Tower-ST Agrate 300mm, TPSCo Japan, Newport Beach Maxim 8”
  • Ecosystem — customers (LWLG, RF/power-mgmt majors), peers, foundry-layer competitors
  • Market — specialty-analog foundry dynamics, AI-photonics adjacency, RF cycle
  • Financials — segment mix, capex cycle, profitability, cash trajectory
  • Market data — price, short interest, post-HFIAA Form 4
  • Thesis — bull / bear / risks / catalysts
  • Sources — primary source catalog
  • Q&A — open questions + author responses