Phase Change Technology

Phase Change Technology

inoptical and electrical memory

applications.

Giuliano MarcoliniBologna 28-05-2012

Classification of memories

• Data type– Analogic memories– Digital memories

• Data retention– Volatile memories– Non-volatile memories

• Data access– Sequental access memories– Random access memories

Classification of memories

Analogic

Memories

Classification of memories

Digital

Analogic

Memoriesvolatile SRAM, DRAM

Classification of memories

Digital

Analogic

Memoriesvolatile

Non-volatile

SRAM, DRAM

ROM,PROM,E(E)PROM

Classification of memories

Digital

Analogic

Memoriesvolatile

Non-volatile

SRAM, DRAM

ROM,PROM,E(E)PROM

Memory Card, SSD

Classification of memories

Digital

Analogic

Memoriesvolatile

Non-volatile

SRAM, DRAM

ROM,PROM,E(E)PROM

Magnetic disk

Memory Card, SSD

Classification of memories

Digital

Analogic

Memoriesvolatile

Non-volatile

SRAM, DRAM

ROM,PROM,E(E)PROM

Memory Card, SSD

Magnetic disk

Optical memory

Classification of memories

Digital

Analogic

Memoriesvolatile

Non-volatile

SRAM, DRAM

ROM,PROM,E(E)PROM

Memory Card, SSD

Magnetic disk

Optical memory

Optical storage:CD-rom

Optical storage:CD-rom

Phase change materials:

Phase change materials:

Tmelt

Tglass

TroomTime [sec]

T [K]

Phase change materials:

Tmelt

Tglass

TroomTime [sec]

T [K]

Phase change materials:

Tmelt

Tglass

TroomTime [sec]

T [K]

Phase change materials:

Tmelt

Tglass

TroomTime [sec]

T [K]

Phase change materials:

Tmelt

Tglass

TroomTime [sec]

T [K]

Phase change materials:

Tmelt

Tglass

TroomTime [sec]

T [K]

Phase change materials:

Tmelt

Tglass

TroomTime [sec]

T [K]

Optical storage:CD-RW

Optical storage:DVD &Blu Ray

CD vs DVD vs Blu-ray Writing

400 nm 700 nm

CD vs DVD vs Blu-ray Writing

400 nm 700 nm

CD vs DVD vs Blu-ray Writing

400 nm 700 nm

Blu-Ray vs HD-DVD

Classification of memories

Digital

Analogic

Memoriesvolatile

Non-volatile

SRAM, DRAM

ROM,PROM,E(E)PROM

Memory Card, SSD

Magnetic disk

Optical memory

Falsh Memory

Phase Change Memories

PCM

Phase Change Memories

R [Ω]

≈ 109 Ω

≈ 105 Ω

Phase Change Memories:memory cell

Top electrode

Phase Change Materials

Resistor(heater)

Bottom electrode

Phase Change Memories:memory cell

I [A]

time

Amorphous

Cristalline

Phase Change Memories:cross-point array

Phase Change Memories

Classification of memories

Digital

Analogic

Memoriesvolatile

Non-volatile

SRAM, DRAM

Magnetic disk

Optical memory

Falsh Memory

PCM

Brief overview:Static and Dynamic RAM

SRAM DRAM

Flash memory cell: Floating gate transistor

Vg

Vs Vd

Brief overview:Flash memory cell

Vg

Vs Vd

PCM vs Flash

• Electric charge • Physical phases

• Write time ≈ 10 µs • Write time ≈ 0.1 µs

• Endurance ≈ 5000 cycle p.s. • Endurance ≈ 107 cycle

• Retention ≈ 50,10,5,2 yr • Retention ≈ 300 yr (at 85°)

• Low radiation res. • High radiation res.

PCMFlash

Questions ?

Thank you and

goodbye !