Hybrid AMHS

Twice the Throughput for Half the Cost


Extremely High Throughput

Inter-Bay & Intra-Bay conveyors typically provide 600 to 800 carriers/hour throughput per direction. Since most distances are covered by conveyors, a typical 30-bay system is capable of over 4500 moves/hour with minimal movement of OHT. Unlike OHT-only systems, traffic jam is nowhere to be seen.

Low Initial & Running Cost

Less than half the number of OHT is required due to its low running distance. With its simple track design combined with a low voltage wireless power system, the initial cost of the system is significantly lower than that of traditional OHT-only system. The cost of ownership of the system is low as OHT workload is extremely low and the conveyors are quasi-maintenance free.

Zero Floor-Standing Stocker

Abundant overhead buffer shelves satisfy entire WIP requirements eliminating the need for any floor-standing stockers.

Adaptable to Low Ceiling Fabs

Despite the two level OHT-Conveyor layout, the minimum ceiling height required is as low as 3.5m, thus enabling its use in older low ceiling Fabs.

Hybrid AMHS Components

Conveyor System + OHT System + Near Tool Buffers

Hybrid AMHS is a Fully-Automated AMHS which provides higher throughput at a fraction of the cost of traditional OHT-only system typically for 200mm and 300mm wafer fabs

  • OHT Vehicle
  • Overhead Buffer Shelves
  • Process Tool Direct
    Load/Unload Ports
  • STRATUS Inter-bay Conveyor
  • STRATUS Intra-bay Conveyor
  • STRATUS I/O Conveyor







  • High throughput backbone conveyor installed in the interbay corridor supports 600+ throughput per lane and over 3000 moves per hour in a typical 26 bay fab.
Overhead Hoist Transport
  • Most bays can be served by only 2 or 3 OHTs while only a few high throughput bays require 4 or more OHTs This translate to about 100 OHTs required as opposed to 250 to 300 OHTs needed for traditional OHT-only system to support 2000 moves
Near Tool Buffer
  • Long reach transverse axis of OHT provides 3 row high density overhead storage which reduces floor space and increases WIP capacity while reducing lot replacement time, eliminating the need for floor-standing stockers.
Manual Load Port
  • I/O Conveyors facilitate transport of lots from other bays to the OHT track for direct loading of OHT from the conveyor system to the tools or vice versa
  • Manual load ports facilitates operators to load lots to overhead conveyor system through direct loading of OHTs
OHT System +
Conveyor System
    • OHT loads lots from tools to I/O conveyors connected to intrabay conveyors which links to interbay conveyor to transport the lots to another bay
OHT System +
Near Tool Buffers
  • OHT loads WIP lot from I/O conveyors to overhead buffer shelves for temporary WIP storage which is then picked up from the overhead buffer shelves and loaded onto the destination tool when the tool is ready for lot processing

Conveyor-Based AMHS

Conveyor-based AMHS is a Semi-Automated AMHS suitable for existing fabs looking for cost-saving solution with to reduce manpower on repetitive tasks and to focus more on high-value tasks

Semi-Automated AMHS requires operator to load the carriers into I/O lifter to lift the carrier onto the overhead conveyors to be transported elsewhere and vice versa. I/O lifter with buffer provides a temporary storage area to stand by for operator to pick up during high-volume delivery

Long Lifter provides inter-floor transport to connect conveyors from different levels up to 20+ meters

Overhead conveyors are the backbone of the conveyor-based AMHS as carriers loaded onto I/O lifters are then lifted onto the overhead conveyors to be transported to the required destination.





  • Semi-Automated AMHS is conveyor-based AMHS which does not require OHTs, further reducing the required initial cost

Limited Ceiling

  • Semi-Automated AMHS is the solution for existing fabs with lower ceiling height available as it does not include OHT which require more space than conveyor-based AMHS

Industrial Segments

Front-End Semiconductor
Back-End Semiconductor
Storage Disk Industries
Solar Cell

Type of Carriers

Reticle Pod
Open Cassette

Discover Our Products

  • Stratus provides a comprehensive chain of product line which includes Transport System, Direct Loading System, Automated Storage and Retrieval System (ASRS), Transport Control System (TCS) and AMHS Solution.

Vast line of products for wide range of applications

Stratus provides a complete turnkey cleanroom AMHS mainly for semiconductor fabs, solar cell, medical industries as well as OEM supplier for many world class semiconductor automation system integrator.


  • Overhead Hoist Transport (OHT)
  • Conveyor
  • Transport Control System (TCS)
  • IntelliMove
  • IntelliStock

Automated Storage
& Retrieval System

  • T-type Stocker
  • R-type Stocker
  • Zero Footprint Stocker (ZFS)