HETEROGENEOUS PROCESSES IN CF4/O2 PLASMAS PROBED USING LASER-INDUCED FLUORESCENCE OF CF2

被引:25
作者
HANSEN, SG [1 ]
LUCKMAN, G [1 ]
NIEMAN, GC [1 ]
COLSON, SD [1 ]
机构
[1] YALE UNIV,STERLING CHEM LAB,NEW HAVEN,CT 06511
关键词
D O I
10.1063/1.346551
中图分类号
O59 [应用物理学];
学科分类号
摘要
Laser-induced fluorescence of CF2 is used to monitor heterogeneous processes in ≊300 mTorr CF4/O2 plasmas. CF2 is rapidly removed at fluorinated copper and silver surfaces in 13.56-MHz rf discharges as judged by a distinct dip in its spatial distribution. These metals, when employed as etch masks, are known to accelerate plasma etching of silicon, and the present results suggest catalytic dehalogenation of CF2 is involved in this process. In contrast, aluminum and silicon dioxide exhibit negligible reactivity with CF2, which suggests that aluminum masks will not appreciably accelerate silicon etching and that ground state CF2 does not efficiently etch silicon dioxide. Measurement of CF2 decay in a pulsed discharge coupled with direct laser sputtering of metal into the gas phase indicates the interaction between CF2 and the active metals is purely heterogeneous. Aluminum does, however, exhibit homogeneous reactivity with CF2. Redistribution of active metal by plasma sputtering readily occurs; silicon etch rates may also be enhanced by the metal's presence on the silicon surface. Polymers contribute CF2 to the plasma as they etch. The observation of an induction period suggests fluorination of the polymer surface is the first step in its degradation. Polymeric etch masks can therefore depress the silicon etch rate by removal of F atoms, the primary etchants.
引用
收藏
页码:2013 / 2021
页数:9
相关论文
共 53 条
[1]   SPATIALLY AND TEMPORALLY RESOLVED LASER-INDUCED FLUORESCENCE MEASUREMENTS OF CF2 AND CF RADICALS IN A CF4 RF PLASMA [J].
BOOTH, JP ;
HANCOCK, G ;
PERRY, ND ;
TOOGOOD, MJ .
JOURNAL OF APPLIED PHYSICS, 1989, 66 (11) :5251-5257
[2]   LASER-INDUCED FLUORESCENCE DETECTION OF CF AND CF2 RADICALS IN A CF4/O2 PLASMA [J].
BOOTH, JP ;
HANCOCK, G ;
PERRY, ND .
APPLIED PHYSICS LETTERS, 1987, 50 (06) :318-319
[3]  
Booth JP, 1987, MATER RES SOC S P, V98, P135
[4]   RELATION OF POLYMER STRUCTURE TO PLASMA-ETCHING BEHAVIOR - ROLE OF ATOMIC FLUORINE [J].
CAIN, SR ;
EGITTO, FD ;
EMMI, F .
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS, 1987, 5 (04) :1578-1584
[5]   X-RAY PHOTOELECTRON AND INFRARED-SPECTROSCOPY OF MICROWAVE PLASMA ETCHED POLYIMIDE SURFACES [J].
CHOU, NJ ;
PARASZCZAK, J ;
BABICH, E ;
HEIDENREICH, J ;
CHAUG, YS ;
GOLDBLATT, RD .
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS, 1987, 5 (04) :1321-1326
[6]   OPTICAL-EMISSION SPECTROSCOPY OF REACTIVE PLASMAS - A METHOD FOR CORRELATING EMISSION INTENSITIES TO REACTIVE PARTICLE DENSITY [J].
COBURN, JW ;
CHEN, M .
JOURNAL OF APPLIED PHYSICS, 1980, 51 (06) :3134-3136
[7]   MECHANISMS OF ETCHING AND POLYMERIZATION IN RADIOFREQUENCY DISCHARGES OF CF4-H2,CF4-C2F4,C2F6-H2,C3F8-H2 [J].
DAGOSTINO, R ;
CRAMAROSSA, F ;
COLAPRICO, V ;
DETTOLE, R .
JOURNAL OF APPLIED PHYSICS, 1983, 54 (03) :1284-1288
[8]   SPECTROSCOPIC DIAGNOSTICS OF CF4-O2 PLASMAS DURING SI AND SIO2 ETCHING PROCESSES [J].
DAGOSTINO, R ;
CRAMAROSSA, F ;
DEBENEDICTIS, S ;
FERRARO, G .
JOURNAL OF APPLIED PHYSICS, 1981, 52 (03) :1259-1265
[9]   MECHANISMS OF DEPOSITION AND ETCHING OF THIN-FILMS OF PLASMA-POLYMERIZED FLUORINATED MONOMERS IN RADIOFREQUENCY DISCHARGES FED WITH C2F6-H2 AND C2F6-O2 MIXTURES [J].
DAGOSTINO, R ;
CRAMAROSSA, F ;
ILLUZZI, F .
JOURNAL OF APPLIED PHYSICS, 1987, 61 (08) :2754-2762
[10]   FLASH PHOTOLYSIS MEASUREMENT OF KINETICS OF CF2 REACTIONS [J].
DALBY, FW .
JOURNAL OF CHEMICAL PHYSICS, 1964, 41 (08) :2297-&