Particle behaviour in an electron cyclotron resonance plasma etch tool

Abstract

Sources of particles in a ciosedcoupled electron cyclotron resonance plasma source used for polysiiicon etch included flaking of a residual film deposited on chamber surfaces and shedding of material from the electrostatic wafer chuck. A large. episodic increase in the number of particles added to a wafer in a clean system is ObSeNed more frequently for a plasma-on than for a gas-only source condition. For film-forming process conditions, particles were added to wafers by a residual film, which was observed to fracture and flake away from chamber surfaces. The presence of a plasma, especially when radiofrequency bias is applied to the wafer, caused more particles to be ejected from the walls and added to wafers than the microwave powers. A study of the effect of electrode temperatures on particles added showed that thermophoretic and gravitational forces are not significant for this electron cyclotron resonance operating configuration. Particles originating from the electrostatic chuck were observed to be deposited on wafers in much larger numbers in the presence of the plasma as compared with gas-only conditions, implying the existence of a large ion drag force.

Plasma Etching Behavior of YOF Coating Deposited by Suspension Plasma Spraying in Inductively Coupled CHF3/Ar Plasma

“…Contamination particles were not observed. Although both the Y2O3 and YOF coatings were deposited by the SPS process under the same conditions, the YOF coating showed less erosion, which means that YOF is chemically more stable than Y2O3 against fluoride etching species, which is in agreement with the previous report by Yoshinobu et al [5].…”

“…In order to prevent the etching phenomena, SiO 2 and Al 2 O 3 are used as plasma-resistant materials of the inner wall of the chamber. However, they turn out to become vulnerable to the fluorocarbon plasma gases as the number of drying etching cycles increases [1,[5][6][7][8]. Recently, Y 2 O 3 , which is more chemically stable to the fluorocarbon plasma than Al 2 O 3 and SiO 2 , has been used as a plasma-resistant material [9].…”

Instantaneous Generation of Many Flaked Particles by Impulsive Force of Electric Field Stress Acting on Inner Wall of Mass-Production Plasma Etching Equipment

“…Thus, elucidating the mechanism of this unpredictable generation is essential for preventing such particle outbreak because these particles result in a number of defective LSI devices and a significant reduction in the production yield. Many researchers have investigated particle generation in plasma processing, [2][3][4][5][6][7][8][9][10][11][12][13] but most of them have focused on particle clouds generated through gas-phase reactions under laboratory conditions as well as on artificially induced standard spherical particles. However, the realization of particlefree processes and equipment requires studies on real contaminant particles in an actual manufacturing environment.…”

Capture of flaked particles during plasma etching by a negatively biased electrode

“…Various techniques have been proposed and implemented for measuring those particles. [4][5][6][7][8][9][10][11][12][13] The majority has been on particle clouds generated by gas phase reactions under experimental conditions or induced standard sphere particles. 1 Wafer inspection tools can obtain the number of particles that exist on a wafer surface.…”