先把标准数字钉死：ISO 14644-1 到底要求多干净

Nail the numbers first: what ISO 14644-1 actually requires

洁净房务的所有动作都要回到一个量化基准，否则就是凭感觉打扫。ISO 14644-1 按每立方米空气中大于等于特定粒径（0.1、0.2、0.3、0.5、1.0、5.0 μm）的粒子最大浓度划分等级，等级数字越小越洁净。落到半导体常用区间：ISO Class 5 为每立方米 ≥0.5 μm 粒子不超过 3,520 颗，典型用于光刻与薄膜沉积；ISO Class 6 为 35,200 颗，典型用于蚀刻与清洗；ISO Class 7 为 352,000 颗，典型用于支持区。最高等级 ISO Class 1 要求每立方米 ≥0.1 μm 粒子不超过 10 颗，只用于最精密的半导体工艺。ISO 14644 系列取代了各国旧标准（如美国 FS 209E），中国对应 GB/T 25915 系列，与 ISO 接轨。为什么容差要压到这个量级？因为 7nm 及以下先进制程对尘埃的容忍度在 0.1 μm 级别——一根头发丝直径约 70 μm，也就是头发丝七百分之一大小的颗粒，就足以让光刻图案偏移或电路短路。近年洁净技术的关注点还从粒子扩展到 AMC（气态分子污染物）与微生物；2025 年中国还发布了 GB/T 46376-2025《洁净室及相关受控环境 运维服务》，把运维服务质量本身纳入标准化。

Every housekeeping action has to trace back to a quantified baseline, otherwise you are cleaning by feel. ISO 14644-1 classifies cleanrooms by the maximum concentration of particles per cubic metre at or above specified sizes (0.1, 0.2, 0.3, 0.5, 1.0, 5.0 µm), with lower class numbers meaning cleaner air. In the semiconductor range: ISO Class 5 allows no more than 3,520 particles per m³ at ≥0.5 µm, typically used for lithography and deposition; ISO Class 6 allows 35,200, typical for etching and cleaning; ISO Class 7 allows 352,000, typical for support zones. The most stringent class, ISO Class 1, permits no more than 10 particles per m³ at ≥0.1 µm and is reserved for the most precise semiconductor processes. The ISO 14644 series replaced earlier national standards such as US FS 209E; China's GB/T 25915 series is aligned with it. Why push tolerance this far? Advanced nodes at 7 nm and below have a dust tolerance in the 0.1 µm range - a human hair is roughly 70 µm across, so a particle about one seven-hundredth of a hair's width is enough to shift a lithographic pattern or short a circuit. Contamination control has also extended beyond particles to airborne molecular contamination (AMC) and microbiology; in 2025 China published GB/T 46376-2025 on operation and maintenance services for cleanrooms and associated controlled environments, standardising the service quality of O&M itself.

ULPA 还是 HEPA：0.12 μm 与 0.3 μm 的分界线

ULPA or HEPA: the line between 0.12 µm and 0.3 µm

过滤是第一道防线，选错等级等于白装。典型的三级配置是：初效过滤器拦截大于 5 μm 的大颗粒（纤维、毛发）；中效过滤器去除 1–5 μm 细尘（花粉、皮屑）；末端 HEPA（H13/H14）或 ULPA 作为最后一关。性能分界很清楚：HEPA 对 0.3 μm 颗粒过滤效率在 99.97% 以上；ULPA 对 0.12 μm 颗粒效率达 99.999%，可将粒子持续去除到 0.12 μm 量级。先进制程的光刻区用 ULPA，这不是营销话术而是物理需求。对精密电子装配（PCB、光学、连接器）而言，行业实践是循环风机组用高效 H14，必要时上 ULPA，并在满负荷工况下验证风量——这一点常被忽略：过滤等级达标但风量在设备满开时不足，层流照样被破坏。同样重要的是密封：滤芯与垫片的轻微旁通泄漏就能抵消高效过滤的全部收益，因此备件里必须常备滤芯与密封件，并把「更换滤芯」和「更换垫片」写成同一条作业。移动式清洁设备同理——用于洁净区的工业吸尘器必须做整机无旁通泄漏验证，只看滤材等级参数没有意义。

Filtration is the first line of defence, and the wrong grade wastes the installation. A typical three-stage arrangement is: pre-filters capturing particles above 5 µm (fibres, hair); intermediate filters removing 1-5 µm fines (pollen, skin flakes); and terminal HEPA (H13/H14) or ULPA as the last barrier. The performance boundary is clear: HEPA removes 0.3 µm particles at 99.97% or better, while ULPA reaches 99.999% on 0.12 µm particles and continuously removes particles down to that size. Lithography areas on advanced nodes use ULPA - a physical requirement, not marketing. For precision electronics assembly (PCB, optics, connectors), industry practice is recirculating air units with high-efficiency H14 or ULPA where required, with airflow validated under load. That last point is routinely skipped: the filter grade passes on paper while airflow at full equipment load falls short, and laminar flow collapses anyway. Sealing matters just as much: minor bypass leakage past filters and gaskets can undo the entire benefit of high-efficiency media, so spare filters and gaskets must be stocked and 'replace filter' and 'replace gasket' should be written as one job. The same applies to mobile equipment - an industrial vacuum used in a cleanroom must be validated for whole-machine bypass-free performance, because a filter media rating alone means nothing.

气流与压差：正压 5–10 Pa、单向流 0.3–0.5 m/s

Airflow and pressure: 5-10 Pa positive, unidirectional flow at 0.3-0.5 m/s

过滤完还不够，洁净空气必须「有组织地」进入车间。业界通行做法是车间内部相对外部维持 5–10 Pa 正压：门一开气流由内向外，把外部脏空气顶回去。核心工序区（如光刻间）与相邻区域的压差要求更高，至少 5 Pa，用于防止交叉污染。气流组织采用垂直单向流：洁净空气由天花板 FFU（风机过滤单元）均匀送下，风速控制在 0.3–0.5 m/s，经晶圆表面后从侧墙回风口排出，使尘埃被「冲」走而不是在生产区打转。半导体洁净室的目标是保持从天花板经高架地板的层流；湍流会截留碎屑并延长其悬浮时间，从而提高沉降到晶圆、掩模或元件上的概率。这条物理规律直接约束清洁作业：任何清洁动作——推车、开阀、抖布——只要制造湍流，就在提高污染概率。因此洁净室有「速度限制」：移动过快会在人、推车或设备后方形成负压区并卷入粒子；动作必须缓慢受控，连弯腰捡工具太快都会让粒子从洁净服的接缝与拉链喷出。清洁排班的正确做法是把重型房务安排在设备维护窗口或非关键工艺时段，而不是随时随地开工。

Filtered air still has to enter the room in an organised way. Common practice maintains 5-10 Pa positive pressure relative to outside: when a door opens, air flows outward and pushes dirty air back. Critical process areas such as lithography bays require a higher differential, at least 5 Pa against adjacent zones, to prevent cross-contamination. Air is organised as vertical unidirectional flow: clean air is delivered evenly from ceiling FFUs (fan filter units) at 0.3-0.5 m/s, passes the wafer plane and exits through sidewall returns, so particles are swept out rather than circulating in the production area. Semiconductor cleanrooms aim to keep laminar air flowing from the ceiling through raised metal flooring; turbulent flow traps debris and keeps it airborne longer, increasing the chance it deposits on a wafer, mask or component. That physics constrains cleaning directly: any cleaning action - pushing a cart, opening a valve, shaking a wipe - raises contamination probability if it creates turbulence. Hence cleanrooms have speed limits: moving too fast entrains particles in the wake behind a person, cart or piece of equipment, so movements must be slow and controlled - even bending down too quickly to pick up a dropped tool can jet particles out of suit seams and zippers. The correct scheduling answer is to place heavy housekeeping inside tool maintenance windows or non-critical process periods, not whenever convenient.

禁扫、禁压缩空气：洁净区房务只有三种合规动作

No brooms, no compressed air: only three compliant housekeeping actions

这是洁净房务最硬的一条纪律，全球通行且写进多数 fab 的作业规程：使用 HEPA 过滤吸尘器，绝不使用扫帚或压缩空气。原因很直白——扫帚把沉降粒子重新扬起，压缩空气把局部污染扩散成全场污染，且高速气流摩擦还会产生静电，静电再吸附粉尘，形成恶性循环。允许的动作只有三类。第一类，HEPA/ULPA 过滤吸尘：用于地面、工作台、设备外壳与机内。第二类，低尘擦拭：低起毛聚酯无纺布配 IPA（异丙醇）擦拭表面，是日常清洁的主力；工器具进入洁净区前也要先用 IPA 擦拭布擦拭。第三类，点位处理：极脆弱表面（如光刻掩模）不可刷拭，标准做法是用小型氮气吹枪把粒子吹离，或用小型真空吸嘴吸走，或两者组合；车间内另设静电吸附机组，通过静电极吸附带电细颗粒并配合机械过滤。粘尘垫（sticky mat）有明确更换判据：覆盖率超过 60% 即更换，入口处的粘尘垫要高频更换。一次性用品用完即弃，不得复用——复用粘尘垫、手套、擦拭布是最常见的低级失误之一。

This is the hardest rule in cleanroom housekeeping, universal across fabs and written into most operating procedures: use HEPA-filtered vacuums, never brooms or compressed air. The reason is direct - brooms re-entrain settled particles, compressed air converts local contamination into facility-wide contamination, and the high-velocity flow generates static that then attracts dust, closing a vicious loop. Only three action classes are allowed. First, HEPA/ULPA filtered vacuuming for floors, benches, tool exteriors and enclosures. Second, low-lint wiping: low-lint polyester wipes with IPA (isopropyl alcohol) are the daily workhorse, and tools must be wiped with IPA wipes before entering the cleanroom. Third, point interventions: extremely fragile surfaces such as lithography masks cannot be brushed, so the standard method is a small nitrogen jet to dislodge the particle, a small vacuum nozzle to remove it, or both in combination; separate static-attraction units placed through the plant pull charged fine particles onto internal poles alongside mechanical filters. Sticky mats have an explicit change-out criterion: replace when more than 60% covered, and replace entry mats frequently. Single-use items are discarded after use and never reused - reusing tack mats, gloves or wipes is one of the most common basic failures.

静电控制：表面电阻 <10¹¹ Ω，与除尘是同一套系统

ESD control: surface resistance below 10^11 ohms, coupled to particle control

静电与尘埃是耦合的：静电吸附尘埃，尘埃摩擦又产生静电，任何一环失控整条产线良率都会受影响，所以两套系统必须同时运行。可执行的量化要求包括：定期测试 ESD 地板与洁净服的表面电阻，控制在 10¹¹ Ω 以下；人员使用腕带并用腕带测试仪按班验证；进入洁净区后、接触晶圆前须先触碰 ESD 安全表面接地。温湿度是静电控制的底层条件——半导体洁净室典型控制在 21±1 ℃、相对湿度 45±5%，目的正是防止静电积累与结露。物料与工具侧，运输须用防静电包装（静电屏蔽袋、导电周转箱）；晶圆只能用真空吸笔或 ESD 安全镊子取放，不得直接放在普通台面上，必须使用洁净室认证托盘。这些规则外延到清洁设备选型：用于电子车间的工业吸尘器必须配防静电吸嘴与导电软管并可靠接地，否则吸尘过程本身就是静电放电源。精密电子行业的房务实践同样强调「只用带防静电工装的工业吸尘器清扫地面、工作台与机内」，并把易起毛服装从装配区清除。

Static and particles are coupled: static attracts dust, and dust friction generates static, so both systems must run together or yield suffers. Executable requirements include: regularly test ESD flooring and garments for surface resistance below 10^11 ohms; issue wrist straps and verify them per shift with a wrist strap tester; touch an ESD-safe surface to ground after entry and before handling wafers. Temperature and humidity are the substrate of static control - semiconductor cleanrooms typically hold 21 ± 1 °C and 45 ± 5% RH precisely to prevent static buildup and condensation. On the material side, transport uses ESD-safe packaging (static-shielding bags, conductive totes); wafers are handled only with vacuum wands or ESD-safe tweezers and never placed directly on surfaces, always on cleanroom-certified trays. These rules extend into equipment selection: an industrial vacuum used in electronics areas must have antistatic tooling and conductive hose, reliably grounded, or the vacuuming process itself becomes an ESD source. Precision electronics housekeeping practice likewise insists on approved industrial vacuums with antistatic tooling for floors, benches and machine enclosures, and on removing fibre-shedding garments from assembly areas.

铜／非铜分区：一把内六角扳手就能毁掉一批晶圆

Copper versus non-copper: one hex wrench can scrap a batch

这条规则外行看着夸张，但在 fab 里是铁律。为控制化学污染，最具破坏性的材料（首推铜）有严格隔离规则：工器具、部件与备件按「用于铜环境」或「用于非铜环境」分别标记；违反这一程序可能导致大规模失效——哪怕是最小的一把内六角扳手，从铜制部件上蹭下一点碎屑就足够。铜区物理隔离，有些 fab 甚至让工作人员穿不同颜色的洁净服，以最小化铜污染人员与非铜人员之间的接触。落到房务上，这意味着清洁工具必须「专机专区」：铜区用的吸尘器、吸嘴、软管、擦拭布、拖把绝不能跨区使用，设备本体要有醒目的区域标识与颜色编码，备件也要分开库存。这是很多外包清洁团队最容易踩的坑——为了「提高设备利用率」把一台吸尘器在多个区域轮转，等于用清洁设备当污染搬运工。同类逻辑还适用于污染物本身：石棉、铅、催化剂粉尘等危险物料在其他行业也要求源头装袋贴标、防止装置间交叉污染，机器与耗材一律分区。

This rule looks excessive from outside and is iron law inside a fab. To limit chemical contamination, strict rules apply to the most impactful materials - copper above all: tool sets, components and spare parts are marked for use in copper or non-copper environments. Violating the procedure can lead to massive failures, even from the smallest hex wrench that sheds a chip from a copper component. Copper areas are separated, and some fabs have workers wear different coloured cleanroom suits to minimise contact between copper-contaminated and non-copper personnel. Translated into housekeeping, cleaning equipment must be zone-dedicated: vacuums, nozzles, hoses, wipes and mops used in copper areas must never cross zones, machines need conspicuous zone identification and colour coding, and spares must be stocked separately. This is the trap outsourced cleaning teams fall into most often - rotating one vacuum across several zones to 'improve utilisation' turns cleaning equipment into a contamination courier. The same logic governs hazardous materials elsewhere: asbestos, lead and catalyst dusts are bagged and labelled at source to prevent cross-contamination between units, with machines and consumables kept zone-separate.

污染源排序：人是第一位，其次是工具与耗材

Rank the sources: people first, then tools and consumables

把资源投在正确位置的前提，是知道污染从哪来。半导体行业的共识是：人员活动是洁净室最大的污染风险。行业资料给出的量级是，一个人每分钟会脱落约 40 万片皮肤碎屑，走动还会卷起地面沉积微粒。因此更衣（gowning）规程被写得极细：全身覆盖，穿 ESD 安全连体服、头罩、鞋套与手套；穿戴顺序为先踩粘尘垫去除鞋底污染，再戴发网与胡须罩，然后穿洁净服并完全拉合拉链，最后戴手套并检查是否破损；禁止化妆品与香水，因为它们同时引入粒子与化学蒸气。行为规则包括减少移动、不触碰暴露皮肤或表面、避免不必要交谈（唾液飞沫会污染晶圆）。进出流程为进入前过风淋去除松散粒子、踩粘尘垫、接触 ESD 接地面；离开时先弃手套等一次性物品，再按相反顺序脱除服装（先手套后洁净服）。设备侧遵循 SEMI S2/S8 半导体设备安全标准，并用预防性维护避免粒子积累。第二类污染源是工具与耗材：非洁净室批准材料（如普通纸张、普通塑料）不得带入；洁净区内尽量避免纸箱等易起毛包装。

Spending effort in the right place requires knowing where contamination comes from. The industry consensus is that human activity is the biggest contamination risk in cleanrooms. Published figures put the order of magnitude at roughly 400,000 skin flakes shed per person per minute, plus re-entrainment of settled particles while walking. That is why gowning procedures are written in such detail: full-body coverage with ESD-safe coveralls, hood, booties and gloves; donning sequence of stepping on the sticky mat to remove shoe contaminants, then hairnets and beard covers, then the cleanroom suit fully zipped, and gloves last with a tear check; no makeup or perfume, because they introduce both particles and chemical vapours. Behavioural rules include minimising movement, not touching exposed skin or surfaces, and avoiding unnecessary talking since saliva droplets can contaminate wafers. Entry means an air shower to remove loose particles, a sticky mat, and ESD grounding; exit means disposing of gloves and single-use items first, then removing garments in reverse order (gloves first, suit last). On the equipment side, follow SEMI S2/S8 semiconductor tool safety standards and use preventive maintenance to avoid particle buildup. The second source class is tools and consumables: non-cleanroom-approved materials such as ordinary paper and standard plastic must stay out, and fibre-shedding packaging like cardboard should be avoided in clean zones.

监测与闭环：把 PM 趋势绑到工艺 hold point

Monitoring and closed loop: tie PM trends to process hold points

洁净房务要形成闭环，靠的是监测数据而不是打扫记录。空气质量侧，用粒子计数器确认达到 ISO Class 5 或更优（≥0.5 μm ≤3,520 颗/m³），并监控压差以维持正压防止污染侵入；许多 fab 部署在线（in-situ）粒子监测，在异常升高影响产品前预警。精密电子装配区的可执行做法是趋势化 PM1/PM2.5，把报警阈值绑定到工艺 hold point：出现尖峰就按固定清单排查——罩口位置、滤芯积尘、门禁纪律。工艺侧用 SPC（统计过程控制）与实时监控识别偏差，用 SEM 与粒子缺陷扫描在流转到下一工序前发现微缺陷，并把缺陷图与工艺数据做相关分析，支撑预测性维护与根因分析。房务侧的日常例行是：低起毛聚酯无纺布配 IPA 擦拭表面、粘尘垫覆盖超 60% 更换、只用 HEPA 过滤吸尘器（绝不用扫帚或压缩空气）。ApexClean（常州永乐环境工程有限公司）为电子与洁净制造客户提供不锈钢桶体工业吸尘机、干湿两用吸尘吸水机与低尘擦拭耗材，配置时请注明所需过滤等级、防静电工装与铜／非铜分区标识需求，以便按区域选型而不是按功率选型。

Housekeeping closes the loop through monitoring data, not cleaning logs. On air quality, use particle counters to confirm ISO Class 5 or better (≤3,520 particles/m³ at ≥0.5 µm) and monitor pressure differentials to maintain positive airflow and prevent ingress; many fabs deploy in-situ particle monitoring to detect abnormal increases before product quality is affected. In precision electronics assembly the executable practice is to trend PM1/PM2.5 and tie alert thresholds to process hold points: on a spike, work a fixed checklist - hood placement, filter loading, door discipline. On the process side, statistical process control (SPC) and real-time monitoring identify deviations, while SEM and particle defect scanners catch micro-defects before wafers advance, with defect maps correlated against process data to support predictive maintenance and root-cause analysis. Daily housekeeping routine: wipe surfaces with low-lint polyester wipes and IPA, replace sticky mats when more than 60% covered, and use HEPA-filtered vacuums only - never brooms or compressed air. ApexClean (Changzhou Yongle Environmental Engineering Co., Ltd.) supplies stainless-steel drum industrial vacuums, wet/dry vacuum units and low-lint wiping consumables for electronics and clean manufacturing customers; when specifying, state the required filtration grade, antistatic tooling and copper/non-copper zone marking so the machine is selected by zone rather than by motor power.