Industrial Feasibility Analysis of SiC TSV Through-Hole Etching Technology

Based on the information I have collected, I will systematically analyze the industrial feasibility of SiC TSV through-hole etching technology for you.

According to technical literature data [1], there is a significant difference in etching rates between silicon and SiC in Deep Reactive Ion Etching (DRIE):

Specific data sources show that:

• The maximum SiC etching rate under optimized conditions reaches
  0.44 μm/min
  [1]
• Modern silicon DRIE systems can reach
  20-25 μm/min
  [2]
• This is basically consistent with the “44 times” data you mentioned

1. Extremely high chemical stability
   : The Si-C bond energy of SiC is extremely high (approx. 318 kJ/mol), far higher than that of the Si-Si bond (222 kJ/mol)
2. High physical hardness
   : Mohs hardness of 9.5, second only to diamond
3. Selectivity issue
   : The SiC/SiO2 selectivity ratio is only 2.8-4.6 under optimized conditions [1]
4. Byproduct volatility
   : The byproducts of SiC etching with SF6 plasma have low volatility

According to NREL and industry analysis data [3]:

• Equipment investment
  : Specialized ICP etching systems have higher prices
• Process time
  : Etching time that is more than 44 times longer significantly increases equipment occupancy costs
• Photomask consumption
  : Lower selectivity leads to greater photomask wear
• Capacity utilization
  : Low etching rate severely impacts wafer production capacity

Despite the huge cost gap, SiC TSV technology still has industrial feasibility, mainly based on the following considerations:

Although the unit price of SiC devices is 2.5-3 times that of IGBTs [6], but:

• System cost reduction
  : Battery capacity can be reduced by 5-10% (due to efficiency improvement)
• Overall performance improvement
  : Power density is doubled
• Simplified heat dissipation system
  : High thermal conductivity reduces cooling requirements

The global SiC market is growing rapidly:

• Market size
  : $810 million in 2024 → $2.64 billion in 2032 (CAGR 15.9%) [7]
• Automotive sector
  : The largest growth driver
• Capacity expansion
  : 8-inch SiC wafers are becoming popular, with yield increased to >85% [6]

1. Application Scenario Screening
   :
   • ✅
     High-value applications
     : Electric vehicle main inverters, industrial frequency converters, rail transit
   • ❌
     Cost-sensitive applications
     : Consumer electronics, lighting drivers (still dominated by silicon)

2. Economic Critical Point
   :
   • When the system cost of SiC devices ≤ that of silicon solutions (considering efficiency gains), it has the economic viability for full replacement
   • It currently has economic viability in 800V high-end vehicle models

3. Technology Maturity
   :
   • In the early maturity stage
   • Expected to reach a cost inflection point between 2027 and 2030

According to analyses by Roland Berger and other institutions [8]:

• SiC manufacturers are actively overcoming cost barriers
• Automotive OEMs are building vertically integrated SiC supply chains
• The next 2-3 years will be a critical period for capacity expansion

[1] CS MANTECH Conference - Optimizing the SiC Plasma Etching Process (https://csmantech.org/wp-content/acfrcwduploads/post_2951/7.1_036.pdf)

[2] Georgia Tech Institute for Matter and Systems - Etching Capabilities (https://matter-systems.gatech.edu/cleanroom/capabilities/etching)

[3] NREL - A Manufacturing Cost and Supply Chain Analysis of SiC Power Electronics (https://docs.nrel.gov/docs/fy17osti/67694.pdf)

[4] Power Electronics - SiC-Based Power Modules Cut Costs for Battery-Powered Vehicles (https://www.power-mag.com/pdf/feature_pdf/1526564789_Infinieon_feature.pdf)

[5] MDPI Micromachines - Recent Advances in Reactive Ion Etching (https://www.mdpi.com/2072-666X/12/8/991)

[6] Trend Analysis - Automotive Power Semiconductor Industry Report (https://www.linkedin.com/pulse/trend-analysis-automotive-power-semiconductor-industry-erick-yang-p285c)

[7] DataMint Intelligence - Silicon Carbide (SiC) Semiconductor Market Forecast (https://www.datamintelligence.com/research-report/silicon-carbide-semiconductor-market)

[8] Roland Berger - Silicon Carbide in Automotive Power Electronics (https://www.rolandberger.com/en/Insights/Publications/Silicon-carbide-in-automotive-power-electronics.html)

Although the 44-fold etching rate gap and dozens of times cost difference do exist, these challenges are gradually being mitigated through measures such as wafer size expansion, yield improvement, and process optimization. In applications with extremely high performance requirements and low system cost sensitivity, such as 800V high-voltage platforms for electric vehicles and industrial power modules, SiC TSV technology has demonstrated significant system-level advantages and economic value. With technological maturity and the emergence of scale effects, it is expected to achieve broader industrial applications between 2027 and 2030.