Sputter Deposition Systems Perkin-ELmer 4410 4450 And 4480 

As new commercial and industrial technologies emerged and grew, so did the use of sputtering as a technique for deposition thin films of desired characteristics. The Perkin Elmer 4400 and 2400 Series sputtering systems were designed to meet the changes of this changing technical environment, whether in development or production.

With an installed base of more than thousands of systems, Perkin-Elmer was a leading supplier of sputter deposition equipment for high technology application in 1990's. The Perkin Elmer 2400 Series sputtering systems were used not only in the production of semiconductor devices but also in the development and manufacturing of thin film recording heads, thin film resistors and capacitors, optical coatings, gallium arsenide lasers and fiber optics.

Quality, performance and stability backed by more than two decades of experience in vacuum technology and UHV design were built into every Perkin Elmer sputtering system. The 4400 and 2400 Series were designed for flexibility offering a wide range of operating and process modes. The highest quality construction and components assure reliable operation and an ultra clean vacuum environment to yield consistently reproducible results. Every Perkin Elmer sputtering system was supported by years of technological experience and backed by a worldwide sales and service organization dedicated to prompt courteous service.

The 4400 and 2400 Series of sputtering systems represent just one part of the Perkin Elmer Semiconductor Equipment Group's unique "one source" approach to cost-effective VLSI production. From mask making to photolithography, dry etching and sputtering deposition, the Semiconductor Equipment Group provides an integrated line of performance-proven production equipment specially designed to address each critical process. This "one source" solutions designed to meet the semiconductor industry's demands throughout the 1980's.

Versatile Systems For Any Sputtering Need

The 4400 Series, designed specially for high throughput production environments, features a high capacity load lock and a broad range of operating models to accommodate virtually any thin film coating requirement.

n      High Throughput

The 4400 Series fast cycle load lock, cryogenic pump, and full flood Meissner trap ensures quick turnaround on batch loads. High throughput are achieved for a full range of substrate sizes and shapes.

n      High Yield

A rotating substrate table for multi-pass deposition helps assure high uniformity and run-to-run repeatability. Simplicity of mechanical design with a minimum number of moving parts in the process chamber minimizes the generation of defect-causing. Easy loading pallet designs reduce wafer breakage. Consistently clean vacuum conditions assure reproducible high quality films.

n      Optimum Process Control

The 4400 Series provides a broad choice of target materials, machine operating models, pressure and gas controls, cathode configurations and power levels. Operating models include DC magnetron, RF magnetron, RF diode, bias sputter, reactive sputter, co-sputter and RF etch.

n      Total Control of Critical Film Characteristics

The 4400 Series systems yield excellent films for a wide variety of materials including aluminum alloys, platinum silicide, titanium-tungsten, nichrome-gold, silicon nitride, silicon dioxide, precious metals and permalloy.

 

Deposition Of Thin Film for VLSI Geometries

4400 Series System configurations

No single cathode design can effectively meet the varied needs of different users or even the possible multiple needs of one user. Every film requires an optimum combination of target material, size, and shape for its most efficient fabrication. Recognizing these realities, the 4400 Series provides two distinct cathode configurations: 8" circular and delta-shaped.

n      4400

A general purpose sputtering system employing up to three 8" diameter circular cathodes in DC magnetron, RF magnetron, or RF diode configurations. Power options are available up to 2 kw RF and 5 kw DC.

n      4410

A delta target sputtering system designed for high rate deposition of metals and metal alloys. The 4410 is also adaptable to the deposition of dielectrics and employs up to three delta-shaped cathodes in DC magnetron, RF magnetron, or RF diode configuration. Power options are available up to 3 kw RF and 10 KW DC.

n      4450

A delta target sputtering system, similar to the Model 4410 with load lock pumping and heating incorporated as standard features.

n      4480

A delta target sputtering system of identical design to Model 4450 but including cassette-to-cassette loading as a standard feature.

 

As VLSI geometries routinely approach the one to two micron region, new problems arise in thin film deposition technology, dry etched vertical walls, deep vias and multiple level structures must all be uniformly covered with no microcracks or cusping. Film deposition systems must be able to provide uniform conformal coverage of these tightly packed structures to minimize interconnect resistances and maximize yields.

Substrate heating has improved step coverage of LSI structures by increasing the surface mobility of the depositing atoms. Additional techniques are now being used to further enhance coverage of planar-magnetron-sputtered films. Perkin Elmer 4400 and 2400 Series sputtering systems utilize "multi-pass" design and RF bias to maximize film coverage of VLSI structures.

As geometrical features get smaller, new materials will be employed. Metallization layers now include the use of diffusion barriers and low resistance gate and interconnect materials such as refractory metal silicides.

Substrate Motion

By utilizing rotating substrate table, Perkin Elmer sputtering systems allow wafers to be coated by multiple passes through the target region. This technique can minimize shadowing effects sometimes encountered in the single pass mode or center-to-edge effects found in static deposition systems, while maximizing target material utilization, step coverage and device yield.

RF Bias

The application of RF bias to the substrate re-sputters deposited material from horizontal surfaces onto the surrounding vertical walls of the wafer. Step coverage of 50% or more can be achieved on vertical steps and deep vias can be uniformity covered with RF bias and multi-pass technologies.

Co-sputtering

The deposition of contamination-free, low-resistance refractory metal silicides request the use of the purest materials. Co-sputtering provides the optimum method for depositing these films from pure elemental targets, wile providing a convenient means to control the stoichiometry of the films. Oxygen and carbon contamination and target-to-target stoichiometric non-uniformities are minimized using dual target sputtering and multi-pass techniques.

 

High Vacuum Technology for Maximum Process Control

n      Fast Cycle Load Lock Operation

The 4400 Series high capacity load lock system eliminates the need to break vacuum; thereby reducing both pumpdown time and contamination of targets and internal chamber surfaces. Transfer of a full pallet load of wafers from air to the process chamber and pumpdown to a base pressure of 5X10^-7  Torr  can be accomplished in less than 3.5 minutes.

n      Contamination-free Cryogenic Pump

The process chamber vacuum system incorporates a contamination-free, closed cycle, two-stage helium cryopump (turbomolecular pump optional). Under load conditions, 70^oK is maintained in the first stage and less than 15^oK in the second stage. This assures efficient, rapid pumping of most atmospheric gases and reduction of partial pressures of most unwanted gas species to acceptable levels. An ultimate vacuum of 10^-6  scale can be attained with typical pumping speeds of 1000 l/s for nitrogen, 1100 l/s for hydrogen and 4200 l/s for water vapor.

n      The Meissner Trap

A full flood Meissner trap mounted in the process chamber maintains an efficient pumping speed for water vapor of 30,000 l/s during deposition or sputter etching. The Meissner trap pumps water vapor at a maximum rate even with the high vacuum cryopump throttled. This assures good quality films in critical processes such as the deposition of aluminum alloys.

n      Substrate Degassing

The 4400 Series systems can be equipment with load lock heating and turbomolecular pumping to degas substrates prior to processing and minimize pumpdown for critical processes such as the deposition of aluminum alloys and other oxidizable metals. This further reduces the partial pressure of undesirable gases such as water vapor.

n      Vacuum Control

All 4400 Series systems are equipped with ion and thermocouple gauges. A wide-range gauge controller monitors and digitally displays vacuum levels from 10^-11 to 200 microns providing continuous monitoring of operating pressure. Additional thermocouples provide inputs to the automatic pumpdown control and automatic lock control.

 

The Circular Cathode Systems-Model 4400

Model 4400 is designed for use in production environments or process development. Up to three 8-inch circular cathodes and a 350^oC quartz lamp heater may be installed in the process chamber to accommodate a variety of processes. An optional RF power sputtering network enables the RF/RF Co-deposition of two different materials. Precise stoichiometries of graded interface may be easily achieved.

The Model 4400 is routinely used for such processes as the deposition of Cr-Co for recording discs, Cr-Cu for backside metallization, TaSi₂ for gate metallization and Si₃N₄ for interlayer dielectric.

Chrome-Cobalt

A precise ratio of chrome to cobalt is readily achieved with co-deposition using the RF power splitting option, ideal film temperature in the range 170 ^oC-200 ^oC can be easily obtained for optimum grain growth and orientation.

Chrome-Gold

The films resulting from the sputter deposition of chrome-gold are superior to those obtained from evaporation processes, pre-etching prior to deposition removes native oxide improving film adhesion and RF magnetron deposition results in lower thin film temperature and less gold interdiffusion.

Tantalum Silicide

Tantalum silicide of any desired stoichiometry is easily deposited with co-sputtering using the RF power splitting module. Annealed film resistivity of approximately 2.3 ohms per square can be obtained from a typical 2000 angstrom film of tantalum silicide. Within further advances in process technology, the UHV design of the 4400 will enable it to accommodate the deposition of refractory metal silicide films of even higher resistivities.

Silicon Nitride

With RF bias deposition, silicon nitride films exhibiting low pin-whole count, good step coverage and low stress can be readily deposited in the model 4400.

The RF Power Split Module

The two-way adjustable RF Power Split Module provides precise control of the level and ratio of RF energy from a single RF generator to two 8" diameter cathodes simultaneously. A total of 2 kw may be applied with power ratio adjustable between 5% and 95%. This module is idea for use with the Model 4400 and 2400-8SA in R&D and in low volume production applications, where precise control of alloying of film properties is desired.

Features

n      Efficient 8" round cathodes

n      High throughput operation

n      High Uniformity

n      DC, RF Etch and Bias operation

n      Ultra Clean vacuum system

n      Load lock operation

n      UHV design

n      Flexible for development or production use

n      Substrates up to 6" diameter

n      Various pumping and power options

n      RF/RF co-sputtering option

n      Optional gas controllers

A Wide Range of Process

The following processes have been demonstrated in the Model 4400

Al+W	Cr/SiO2	SiC	Ti+Au
Al+Ti/W+Ag	InSnO	SiO2	Ti+Au+Ni
Al2O3	Mo	SiO2+O2	Ti/W
Ag	MoSi2	Si+N2(Si3N4)	Ti/W+Au
Au	Mo2Si5	Si+N2+B4C	Ti/W+Au+Ta
C	Mo5Si3	Ta	Ti/W+Al/Si
Cr	Ni	TaC	Ti/W+Ni/Cr+Au
Cr/Co	Ni/Cr	Ta+Au	Ti/W+Pt
Cr/Au	Ni+Ni/Cr	TaSi2	W
Cr+Cu	Ni/Fe	Ta+SiO2	W+Al2O3
Cr/Si	Ni/Fe+Cu+SiO2	TiO2	Zn
Cr/SiO	Pt	TiO2+Cr	ZnO2
			Zr

Aluminum Alloy Sputtering

The Perkin Elmer Delta cathode systems(Model 4410, 4450, 4480) are ideally suited to aluminum alloy deposition for gate contact and interconnect metalization.

n      Utilization and Rate

A Delta cathode system achieves an instantaneous deposition rate for aluminum alloys of 12,000 angstroms/minute. The substrate pallet can be in excess of 200 angstroms/kw minute with sputtered material utilization approaching.

n      Uniformity and throughput

Delta cathode systems maximize uniformity of deposition, exhibiting a +/-7% uniformity over a 6" annular width. Optional high performance Delta cathodes yield a uniformity of +/-5% over a 7³/₄ inch band, allowing processing of up to 22 100mm wafers per cycle. Standard Delta cathodes process 50-60 100mm wafers per hour while optional high performance Delta cathodes yield throughput in excess of 80 100mm wafers per hour.

A particular advantage of a circular batch sputtering system is its adaptability to different substrate sizes. The Model 4410 and other delta cathode systems can easily handle substrate size up to 8 inches in diameter. Standard wafer size of 3 inch, 100mm, 125mm and 150mm can easily be accommodated.

TYPICAL CAPACITY-UNIFORMITY DATA
Wafer Size	Loading Capacity	Deposition Uniformity
		Std Delta	High Perf. Delta
3inch	30	+/-7%	+/-5%
100mm	22	N/A	+/-5%
	14	+/-7%	+/-4%
	13	+/-5%	+/-4%
125mm	10	+/-7%	+/-5%
	9	+/-4%	+/-4%
150mm	8	+/-12%	+/-5%
	7	+/-7%	+/-4%
8inch	5	+/-14%	+/-7%

The Delta Cathode Systems-4410/4450 And 4480

n      Resistivity

Perkin Elmer sputtering systems ensure low film resistivity by minimizing partial pressure of oxygen and nitrogen below 1X10^-7 Torr. With total system background pressure of 5X10^-7 Torr and an instantaneous deposition rate in excess of 8500 angstroms/minute, near-bulk resistivity for aluminum alloy films can be achieved.

n      Film Hardness

By keeping oxygen content below, film hardness for typical 1 micron thick aluminum silicon films can be kept below 100 kg/mm² after annealing at 500^oC, minimizing bonding failures.

n      Specularity

High quality aluminum alloy films of 70-90% relative reflectance are routinely produced in high rate DC Delta magnetron systems, yielding wafers easily accommodated in today's projection mask aligners.

Optional load lock pumping and wafer degassing further minimize water vapor and hydrogen, the principal contaminants that contribute to hillock growth and poor specularity. As metallization films become thicker and specularity degrades, further reduction of unwanted gases can be achieved through the use of supplemental hydrogen getter pumping in the Model 4410 and other Delta cathode systems.

n      Step Coverage

The high rate sputtering made possible with Perkin Elmer Delta DC magnetron cathodes produces sufficient heat to maintain film temperature in the ideal range. Heating the substrate in this manner and re-sputtering the deposited material through RF bias improves coverage of vertical surfaces in VLSI structures. It also minimizes cracks and cusping.

n      Optional High Performance Delta Cathodes

Provide more uniform deposition over a wider annular region of the pallet. A maximum of twenty two 100mm wafers can be loaded yielding 50% more throughput for a typical metallization process. The HIGH THROUGHPUT option consists of a modified shaping aperture, a high performance Delta cathode and a pallet nested for twenty two 100mm wafers. The region of high uniformity is extended across the total 8" annular width of the pallet. A uniformity of +/-7% is achieved across a  7³/₄ inch band suitable for mounting two concentric rows of 100mm wafers. This wide brand of uniformity means that 5¹/₄", 8", or 14" recording discs can be accommodated in the system.

n      The Delta Cathode Dual Deposit Sputter Module

The Delta Cathode Dual Deposition Sputter Module, operable in either a dual DC mode or DC and RF mode, is designed for higher throughput and larger scale production. Separate power suppliers allow independent application of either DC or RF energy to two delta cathodes simultaneously. The dual deposit sputter module for Models 4410, 4450 and 4480 is the choice for co-sputtering of refractory metal silicides  for VLSI circuits. The dual deposit sputter modules and the co-sputtering technique allow the deposition of contamination-free films.

Features:

n      High rate Delta DC magnetron

n      High throughput operation

n      Fully process characterized for aluminum alloys

n      High uniformity

n      DC, RF, Etch, and Bias operation

n      Ultra clean vacuum system

n      Load lock operation

n      UHV design

n      Flexible for development or production use

n      Any size substrates up to 8" diameter

n      Various pumping and power options

n      Optional system and process controllers

n      Cassette to cassette operation(Model 4480)

n      Co-sputter option for silicides

n      Operation gas controller

 

 

PERFORMANCE FOR TYPICAL METALLIZATION PROCESS-100mm WAFERS
	Standard Delta System	High Throughput Delta Systems
Pallet capacity	14	22
Uniformity	+/-7%(63/4") band	+/-5%(73/4" band)
		+/-7%(8" band)
Typical Target Life	3220 wafers	4070 wafers
Typical Deposition Rate	200 Angstroms/kw-min	170 Angstroms/kw-min
Typical Deposition time	5 minutes	5.9 minutes
*Runs per hour	4.0	3.8
Throughput	56 wafers/hour	83 wafers/hour
* Assumes 10 minute pumping, wafer exchange and venting cycle, some processes require pre-heating, extending the loading cycle by as much as 5 minutes.

 

Delta Cathode Systems Performance Specifications(Typical)
Material	Al/1%Si	Al/1%Si/2%Cu	Al/4%Cu
DC Power	10 kw	10 kw	10 kw
RF Bias	-25V	-25V	-25V
Base Pressure	5X10-7 Torr	5X10-7 Torr	5X10-7 Torr
Pumpdown Time	3.5 min.	3.5 min.	3.5 min
Argon Pressure	8X10-3 Torr	8X10-3 Torr	8X10-3 Torr
Table Rotation	2-5 rpm	2-5 rpm	2-5 rpm
Deposition Rate	2000 ? /min	2000 ? /min	2000 ? /min
Film Temp(max)	375oC	375oC	375oC
Film Thickness	1.0 microns	1.0 microns	1.0 microns
Step Hight	1.0 microns	1.0 microns	1.0 microns
Step Slop/Coverage	70o/70%	70o/70%	70o/70%
	80o/60%	80o/60%	80o/60%
	90o/50%	90o/50%	90o/50%
Specularity	70-75%	80-85%	90-95%
Resistivity	2.85-2.90¦Ì¦¸-cm	2.95-3.00¦Ì¦¸-cm	2.95-3.00¦Ì¦¸-cm
Grain Size	1-2¦Ìm	0.3-0.5¦Ìm	0.3-0.5¦Ì
Film Hardness (Annealed)	85kg/mm2	100kg/mm2	120kg/mm2
CV Shift	0.25V	0.15V	0.15V
*Uniformity	+/-7%	+/-7%	+/-7%
* Typical results with Standard Delta Cathodes. Higher uniformity and throughput can be achieved with high performance Delta Cathodes and high throughput option. Throughput is process dependent and may vary depending on etch and pre-heat cycles.