29,067 technical terms and definitions
alloy junction 1952 maintain selected composition, normal freezing segregation coefficient drift, resistivity tolerance band pull schedule
Grow a Uniform Single Crystal: Fighting the Drift Normal Freezing Introduces on Its Own Nobody has to deliberately change this melt's composition during the pull — step two…
alloy junction 1952 bring both indium disks liquid state, thermal lag front back face conduction, symmetric heating melt onset synchronization
Heat the Assembled Device: Two Disks That Don't Start From the Same Place This is the step where step eleven's peak temperature finally gets reached for real, and where…
alloy junction 1952 non destructive inspection after alloying, frozen fillet contact angle wetting inspection, button volume estimate of dissolved germanium depth
Inspect the Alloyed Assembly: Reading a Closed Structure From the Outside Every inspection in this series since Step 4 has had something to look at directly — a bare crystal…
alloy junction 1952 support thin germanium piece assembly, flexural rigidity thin plate deflection wafer, fixture contact stress concentration fracture
Load the Positioning Fixture: Where Step Six's Thickness Choice Becomes a Handling Risk Step six's thickness choice was framed as a trade between wafer count and fragility — more…
alloy junction 1952 secure the element and check terminal separation, tolerance stack up and thermal expansion terminal clearance, air gap voltage withstand breakdown terminal separation
Mount and Inspect the Assembly: A New Kind of Isolation Risk Step 36 confirmed the bare device passed isolation, rectification, and transistor action on the bench, with nothing…
alloy junction 1952 check leakage gain voltage limits capacitance frequency response, junction depletion capacitance versus reverse bias, base transit time cutoff frequency base width
Perform Final Electrical Tests: A Second Number W_B Was Always Going to Set Step 36 measured current gain and closed the loop on this series' single most-tracked quantity…
alloy junction 1952 melt and partially alloy disk secure, tack firing dissolution budget thermal diffusion, firing time self limiting penetration depth
Perform the First Firing: A Tack Weld, Not the Alloying Cycle This firing shares a furnace and a melting metal with the controlled alloying cycle roughly six steps from now, but…
alloy junction 1952 remove surface material bridging junction boundaries, parasitic surface bridge parallel resistance junction, restore reverse junction resistance post alloy etch
Perform Post-Alloy Etching: Breaking a Parasitic Bridge, Not Cleaning a Surface It would be easy to mistake this step for Step 8's cleanup etch happening a second time, later…
alloy junction 1952 position first disk on one face, collector emitter lateral diffusion collection efficiency, disk placement reference origin alignment
Place the Collector Disk: Why It Goes On Larger, and Why It Goes On First RCA's documented example placed a collector disk measurably larger than the emitter disk that would later…
alloy junction 1952 position second disk opposite face, blind placement mirrored target fixture flip, compounded placement error root sum square
Place the Emitter Disk: Placing Blind Against a Reference You Cannot See The collector went on a face anyone could watch directly; the emitter goes on the opposite face of…
alloy junction 1952 contact exposed n type germanium, ohmic contact schottky barrier work function, base tab keep out zone junction exclusion
Position the Base Tab: The One Contact That Isn't Supposed to Form a Junction Every metal this process has placed on the wafer so far was chosen specifically to dissolve germanium…
alloy junction 1952 prepare high purity germanium, recombination center minority carrier lifetime, indium alloy base material purity requirement
Prepare High-Purity Germanium: Why Recombination Centers, Not Just Donor Atoms, Set the Purity Bar This is the first of forty-two steps describing RCA's 1952 staged alloy-junction…
alloy junction 1952 control purity mass dimensions surface condition, solidus liquidus indium germanium phase diagram, pellet mass germanium dissolution budget
Prepare Indium Disks or Pellets: The Solvent Is the Dopant, Not a Separate Addition to One Every grown-junction-style process introduces an acceptor dopant as a small, calculated…
alloy junction 1952 prevent contamination from tab or attachment materials, galvanic couple nickel germanium etch bath, faraday law galvanic etch depth contribution
Protect the Base Attachment During Etching: A Second Metal Changes the Chemistry Step 30's etch rate law, , assumed a single material sitting in the bath: germanium, dissolving…
alloy junction 1952 remove etchant processing residues, indium wetting contact angle surface energy, wetted fraction alloyed contact area
Rinse and Dry: Why This Etched Surface Has to Wet, Not Just Be Clean There is no junction anywhere in this wafer yet, so the mobile-ion drift that makes rinsing critical much…
alloy junction 1952 multi cycle fresh water rinse after etching, diffusion limited clearance of trapped rinse contaminant, geometric decay residual contamination rinse cycles
Rinse and Dry Thoroughly: Why "Thoroughly" Means Repeated, Not Longer Step 9's rinse, back in Phase 1, was clearing loose particulate off a bare slice with no electrical stakes…
alloy junction 1952 conductivity quality requirements, measurement guard band accept threshold, resistivity structural soundness combined selection
Select Usable Crystal Sections: Why the Accept Band Has to Be Narrower Than the Spec Band Step four handed over a measured resistivity curve and a structural pass/fail — this step…
alloy junction 1952 cut thin pieces single crystal, alloy junction 1952 kerf loss wafer count, slice thickness base width upper bound
Slice the Germanium: Fixing the One Number Nothing Downstream Can Ever Exceed Unlike a cut through a grown-junction ingot, nothing about where or how this crystal gets sliced…
alloy junction 1952 freeze the leftover indium germanium liquid, eutectic freeze indium germanium alloy button, shrinkage void fraction alloy button solidification
Solidify the Residual Alloy Buttons: The Same Melt, Two Different Fates Every step from 20 through 27 has followed the fraction of the indium-germanium liquid sitting directly…
alloy junction 1952 thickness usable area before pellet placement, usable area map exclusion zone wafer, placement margin pellet footprint tolerance
Verify Finished Slice Dimensions: Closing Phase One With One Gate, Not Four Separate Ones Four separate steps have each quietly set their own requirement on this wafer — step…
alloy junction 1952 establish intimate metal semiconductor contact, capillary viscous spreading time constant, young laplace pressure trapped void wetting
Wet the Germanium Faces: Reaching Equilibrium Isn't Instant Step nine established the equilibrium condition wetting needs — a clean surface the molten metal would eventually…
alloy junction transistor, fused junction transistor, indium dots germanium, GE 2N107, John Saby, General Electric 1951, RCA alloy transistor
An alloy-junction transistor is a bipolar junction transistor made by melting small dots of a metal, usually indium, into opposite faces of a thin wafer of germanium so that each…
alloy-junction transistor process flow, alloy junction transistor device process flow, alloy junction transistor process, indium pellet alloying germanium, alloy junction base width control, alloy transistor yield control
Alloy-Junction Transistor Device Process Flow: Pellet Geometry, Soak-Time Kinetics & Furnace-Recipe Yield Control The alloy-junction transistor was the first transistor…
device physics
Alloy Scattering is the mobility-degrading mechanism specific to semiconductor alloy channels where random atom placement creates local potential fluctuations — it penalizes…
ring allreduce bandwidth optimal, recursive halving doubling, allreduce algorithm comparison, nccl allreduce implementation
AllReduce Collective Communication is the fundamental distributed operation that combines (reduces) values from all participating processes and distributes the result to every…
stanford, instruction
Stanford Alpaca is the model that started the open-source instruction-tuning revolution in March 2023 — demonstrating that fine-tuning Meta's LLaMA-7B on just 52,000…
training techniques
Alpaca is an instruction-tuned model line trained from synthetic instruction datasets derived from larger teacher models - It is a core method in modern LLM training and safety…
evaluation
AlpacaEval is an automated evaluation benchmark for instruction-following language models that uses a strong LLM as judge (typically GPT-4) to compare model outputs against…
alpha 21064, what is alpha 21064
Alpha 21064 was the first implementation of Digital Equipment Corporation’s Alpha architecture. Introduced in the early-1990s Alpha program, it embodied a 64-bit RISC architecture…
alpha beta, alpha-beta search, McCarthy 1956, Knuth and Moore 1975, move ordering, game tree pruning, principal variation search
Alpha-beta pruning is an optimization of minimax search that skips branches of a game tree once it is certain they cannot change the final decision, so that it returns exactly…
alpha, common-base current gain, α, hFB, emitter-to-collector transfer ratio, point-contact alpha greater than one
Alpha (α) is the common-base current gain of a bipolar transistor: the ratio of collector current to emitter current, written α = IC / IE. Because the base steals a small slice…
soft errors, radioactive packaging impurities, memory bit flip, low-alpha materials, DRAM reliability
Alpha-particle errors are soft errors in memory chips caused specifically by alpha particles — helium nuclei emitted by the radioactive decay of trace impurities, often in…
internal testing, pre-beta test
Alpha testing is internal pre-release testing performed by development teams or selected internal users - Alpha phases focus on functional completeness defect discovery and core…
code ai
AlphaCode is DeepMind's AI system designed to generate code at a competitive programming level, capable of solving novel coding problems requiring algorithmic reasoning…
protein structure, deepmind
AlphaFold is the AI system developed by Google DeepMind that solved the 50-year grand challenge of protein structure prediction — determining a protein's precise 3D atomic…
healthcare ai
AI-powered diagnostics uses machine learning to assist in disease detection and diagnosis — analyzing symptoms, test results, imaging, and patient history to suggest possible…
protein structure prediction, protein folding neural network, alphafold2, esmfold, protein language model
AlphaFold is the deep learning system developed by DeepMind that predicts the three-dimensional structure of proteins from their amino acid sequence — solving a 50-year-old grand…
alphafold2 evoformer, msa multiple sequence alignment, protein folding ai, rosettafold structure prediction
AlphaFold2 Protein Structure Prediction: Evoformer Architecture and MSA Integration — revolutionizing biology via transformer-based structure prediction AlphaFold2, developed…
AlphaZero Self-Play Search Introduction & Motivation AlphaZero Self-Play Search addresses a central problem in sequential decision making via deeprl: how to Learn a policy that…
AlphaZero Self-Play Search (Extended Study) Introduction & Motivation AlphaZero Self-Play Search (Extended Study) addresses a central problem in sequential decision making via…
AlphaZero Self-Play Search (Extended Study) Introduction & Motivation AlphaZero Self-Play Search (Extended Study) addresses a central problem in sequential decision making via…
als, recommendation systems
ALS is alternating least squares optimization for collaborative filtering with regularized matrix factorization - User and item factors are solved iteratively in closed-form…
als, recommendation systems
ALS Implicit is alternating least-squares matrix factorization adapted for implicit-feedback recommendation data. - It learns user-item latent factors from clicks views and play…
aluminum silicon copper alloy
AlSiCu AlSiCu is an aluminum alloy containing silicon and copper. Connect the name to its role Document whether this film is a target, mask, liner, electrode or temporary layer…
declarative, visualization
Altair: Declarative Visualization for Python Overview Altair is a statistical visualization library for Python, based on Vega-Lite. It is "Declarative", meaning you describe…
MITS, Intel 8080, computer kit, hobbyist movement, Microsoft BASIC, S-100 bus
The Altair 8800 was a build-it-yourself computer kit introduced by the company MITS in 1975, widely credited with igniting the personal-computer hobbyist movement and often…
alternating psm, altpsm, lithography
Alternating Phase-Shift Mask (AltPSM) is an advanced photomask technology where adjacent clear features transmit light with opposite phases (0° and 180°), creating destructive…
environmental & sustainability
Alternative Chemistries is replacement of conventional process chemicals with lower-impact options that maintain technical performance - It supports decarbonization, toxicity…
one-tailed vs two-tailed test, statistical vs practical significance, A/B testing hypothesis
The alternative hypothesis is the claim a hypothesis test is actually designed to find evidence for — typically that a real effect, difference, or relationship exists, directly…
altitude oxygen partial pressure reliability prediction, altitude oxygen partial, oxygen partial pressure, partial pressure reliability, altitude oxygen
Altitude Oxygen Partial Pressure Reliability Prediction with Machine Learning Introduction & Motivation Altitude Oxygen Partial Pressure Reliability Prediction with Machine…