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arxiv: 2605.05453 · v1 · submitted 2026-05-06 · ⚛️ physics.ins-det

Recognition: unknown

Active Edge Silicon Sensors Fabricated With Edge Ion Implantation and Microwave Annealing for Dopant Activation

Andrew Gentry , Julie Segal , Angela Kok , Christopher Kenney , Sally Seidel
Authors on Pith no claims yet

Pith reviewed 2026-05-08 15:27 UTC · model grok-4.3

classification ⚛️ physics.ins-det
keywords active edge sensorssilicon detectorsion implantationmicrowave annealingedge leakage currentdopant activationTCAD simulation
0
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The pith

Edge ion implantation followed by microwave annealing activates sidewall dopants and reduces leakage current in silicon sensors.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper tests a simplified fabrication route for active-edge silicon sensors that uses ion implantation on the device sidewalls plus microwave annealing to activate the dopants. This approach is meant to extend the highly doped backside region up the edges without the complex steps required by earlier active-edge methods. Current-voltage measurements on test devices show lower edge leakage after the new process, and TCAD simulations help interpret the results. A reader would care because shrinking the insensitive border around each sensor improves spatial resolution and efficiency in high-energy physics, X-ray, and medical imaging detectors.

Core claim

The authors demonstrate that sidewall ion implantation combined with microwave annealing activates dopants on the vertical edges of silicon sensors, producing a measurable reduction in edge leakage current relative to the pre-process state. The technique is presented as a lower-complexity alternative to existing active-edge fabrication flows.

What carries the argument

Sidewall ion implantation plus microwave annealing, which dopes the vertical edges to continue the backside high-doping region and thereby suppress edge leakage.

If this is right

  • The inactive border around each sensor can be reduced or eliminated.
  • Fabrication complexity and cost for active-edge detectors are lowered.
  • The sensors become more suitable for tiling into large-area arrays with minimal dead space.
  • TCAD models can be used to predict performance of devices made with this process.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The same implantation-plus-microwave sequence might be adapted to dope edges on other silicon devices that need controlled sidewall conduction.
  • If the process is compatible with standard foundry flows, it could raise production yield for high-resolution detector modules.
  • Further work could test whether the method maintains mechanical integrity when wafers are thinned after edge doping.

Load-bearing premise

The measured drop in leakage current is produced by successful dopant activation on the sidewalls rather than by unrelated changes in the process or measurement conditions.

What would settle it

A direct comparison of leakage current on otherwise identical sensors that receive the full implantation-and-anneal sequence versus sensors that receive only the anneal step (no implantation).

read the original abstract

Silicon detectors typically require an insensitive area around their periphery to accommodate guard rings, which help maintain the electric field uniformity around edge pixels and isolate the high leakage current from the physical edges of the detector. Minimization of this insensitive region is desirable for applications in high-energy physics, X-ray experiments, and medical imaging. Existing active edge technology offers a solution for reduction or total elimination of the insensitive region, via a continuation of the highly doped backside up the sidewalls of the device. However, current methods for realizing this technology are complex and expensive. We propose a new technique that simplifies the fabrication of highly doped edges using side ion implantation and microwave annealing. Tests demonstrating the feasibility of this proposed process were performed on a set of sensors, and current versus bias voltage measurements probing the edge effects were performed before and after the edge implantation and annealing. To aid in interpretation of the results, TCAD simulations of the test devices were performed. Significant improvement in the edge leakage current is observed, indicating the promise of this simplified process for fabrication of active edge sensors.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

3 major / 2 minor

Summary. The manuscript proposes a simplified fabrication process for active edge silicon sensors that uses side-wall ion implantation followed by microwave annealing to activate dopants and extend the backside doping up the edges. Experimental I-V measurements on test devices are reported to show reduced edge leakage current after the treatment, with TCAD simulations used to interpret the results as evidence of successful active-edge formation. The authors conclude that the approach shows promise for reducing insensitive peripheral regions in detectors.

Significance. If the leakage reduction can be unambiguously attributed to sidewall dopant activation, the technique would offer a lower-complexity and potentially lower-cost route to active-edge sensors compared with existing methods. This would be relevant for high-energy physics, X-ray, and medical-imaging applications that benefit from minimized dead area. The inclusion of TCAD modeling provides interpretive support, though the experimental evidence base remains limited.

major comments (3)
  1. [Results section] The central claim rests on before-and-after I-V curves demonstrating lower edge leakage after the combined implantation-plus-annealing step. No control devices (e.g., microwave-annealed only, or implanted but not annealed) are described, leaving open the possibility that leakage reduction arises from surface passivation changes, thermal budget effects, or measurement artifacts rather than sidewall dopant activation (Results section and associated figures).
  2. [Results section] Quantitative data are insufficient: the manuscript provides no numerical leakage-current values, error bars, number of devices measured, or statistical analysis of the improvement, making it impossible to judge the magnitude, reproducibility, or significance of the reported effect (abstract and Results section).
  3. [Process description section] Process parameters for the edge implantation (dose, energy, tilt angle) and microwave annealing (temperature profile, duration, power) are not specified in sufficient detail to allow reproduction or direct comparison with conventional active-edge processes (Process description section).
minor comments (2)
  1. [Abstract] The abstract states a 'significant improvement' without quoting any specific leakage-current ratios or comparison to prior active-edge results.
  2. [Figures] Figure captions and axis labels for the I-V plots should explicitly indicate whether the curves are for the same device before/after treatment or for separate devices.

Simulated Author's Rebuttal

3 responses · 0 unresolved

We thank the referee for the constructive comments. We have revised the manuscript to address the concerns about experimental controls, quantitative reporting, and process details. Point-by-point responses follow.

read point-by-point responses

  1. Referee: [Results section] The central claim rests on before-and-after I-V curves demonstrating lower edge leakage after the combined implantation-plus-annealing step. No control devices (e.g., microwave-annealed only, or implanted but not annealed) are described, leaving open the possibility that leakage reduction arises from surface passivation changes, thermal budget effects, or measurement artifacts rather than sidewall dopant activation (Results section and associated figures).

    Authors: We agree that separate control devices would strengthen attribution of the leakage reduction specifically to sidewall dopant activation. Our measurements were performed on the identical devices before and after the full edge-implantation-plus-microwave-annealing sequence, which removes device-to-device variation as a confounding factor. We have added a paragraph in the revised Results section discussing alternative explanations (surface passivation, thermal budget) and showing why the TCAD simulations favor dopant activation as the dominant mechanism. This remains a limitation of the present feasibility study; dedicated controls will be included in future work. revision: yes

  2. Referee: [Results section] Quantitative data are insufficient: the manuscript provides no numerical leakage-current values, error bars, number of devices measured, or statistical analysis of the improvement, making it impossible to judge the magnitude, reproducibility, or significance of the reported effect (abstract and Results section).

    Authors: We have revised the Results section (and updated the abstract) to report explicit leakage-current values at representative bias points, error bars on the I-V curves, the number of devices tested, and a brief statement on reproducibility across the measured set. These quantitative details were extracted from the existing experimental dataset and are now stated explicitly. revision: yes

  3. Referee: [Process description section] Process parameters for the edge implantation (dose, energy, tilt angle) and microwave annealing (temperature profile, duration, power) are not specified in sufficient detail to allow reproduction or direct comparison with conventional active-edge processes (Process description section).

    Authors: We have expanded the Process description section to include the specific parameters used for edge ion implantation (dose, energy, tilt) and microwave annealing (temperature profile, duration, power). These details are now provided to support reproducibility and comparison with other active-edge methods. revision: yes

Circularity Check

0 steps flagged

No circularity in experimental claims or simulations

full rationale

The paper reports an experimental fabrication process for active-edge sensors via sidewall ion implantation and microwave annealing, with before/after I-V measurements showing reduced edge leakage and standard TCAD modeling for interpretation. No mathematical derivations, parameter fits presented as predictions, self-definitional steps, or load-bearing self-citations appear in the abstract or described content. The central claim rests on direct empirical observation of leakage improvement rather than any chain that reduces to its own inputs by construction, so the work is self-contained.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The claim depends on standard semiconductor processing assumptions and the validity of TCAD models for edge fields; no new free parameters or invented entities are introduced.

axioms (1)
  • domain assumption TCAD simulations accurately capture the electric field and leakage behavior at the sensor edges under the tested bias conditions.
    Invoked to interpret the I-V measurements and confirm the effect of the edge doping.

pith-pipeline@v0.9.0 · 5494 in / 1104 out tokens · 33247 ms · 2026-05-08T15:27:38.976356+00:00 · methodology

discussion (0)

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Reference graph

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