US 5,963,327 AGranted

Total internal reflection electromagnetic radiation beam entry to, and exit from, ellipsometer, polarimeter, reflectometer and the like systems

AssigneeJ.A. Woollam Co., Inc.

InventorsPing He, Blaine D. Johs, Craig M. Herzinger

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Abstract

Disclosed are laterally compact ellipsometer, polarimeter, reflectometer and the like material system investigating systems, and methods for their use. Input and output optical elements effect changes in orientation, (propagation direction), of a beam of electromagnetic radiation caused to pass therethrough by an essentially total internal reflection therein. In addition, a propagation direction diverted beam of electromagnetic radiation can be simultaneously, optionally, caused to have a phase retardation entered between orthogonal polarization components thereof by at least one of the input and output optical elements. The present invention enables relatively simple investigation of a sample system with a polarized beam of electromagnetic radiation which impinges thereupon at a less than Brewster Angle, small "spot" size effecting angle-of-incidence, with respect to a normal to a surface of an investigated material system.

Claims19

Dependent claims

A material system investigating system selected from the group consisting of:

ellipsometer;
polarimeter;
and
reflectometer systems;
said material system investigating system comprising:
a. a light source (LS);
b. a polarizer (P);
c. a first optic element (PRI);
d. a first focusing optic (F1);
e. a material system stage (STG);
f. a second focusing optic (F2);
g. a second optic element (PRO);
h. an analyzer (A);
i. a detector (DET);
and
j. optionally compensator(s) (C) (C');
said light source (LS) and polarizer (P), serving in use to produce a generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBI), said generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBI) being caused to interact with said first optic element (PRI) and by essentially total internal reflection therein become other than a generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBI') which is caused to pass through said first focusing optic (F1) and interact with a material system (MS) placed upon said material system stage (STG), said interaction with said material system (MS) causing a reflected other than generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBO') to pass through said second focusing optic (F2) and interact with said second optic element (PRO), in which second optic element (PRO) said generally other than horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBO') is, by essentially total internal reflection, caused to become a generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBO), which generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation then (LBO) then passes through analyzer (A) and, via an essentially circular shaped aperture (AP), enters said detector system (DET) for analysis, which generally other than horizontally oriented propagation direction, polarized beams of electromagnetic radiation (LBI') and (LBO') approach and are reflected from, respectively, said material system (MS) at essentially equal angles of incidence and reflection (.crclbar.), as viewed in frontal elevation.

14 more elements

A method of investigating a material system comprising the steps of:

a. providing a material system investigating system comprising:
a. a light source (LS);
b. a polarizer (P);
c. a first optic element (PRI);
d. a first focusing optic (F1);
e. a material system stage (STG);
f. a second focusing optic (F2);
g. a second optic element (PRO);
h. an analyzer (A);
i. a detector (DET);
and
j. optionally compensator(s) (C) (C');
said light source (LS) and polarizer (P), serving in use to produce a generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBI), said generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBI) being caused to interact with said first optic element (PRI) and by essentially total internal reflection therein become a generally vertically oriented propagation direction, polarized beam of electromagnetic radiation (LBI') which is caused to pass through said first focusing optic (F1) and interact with a material system (MS) placed upon said material system stage (STG), said interaction with said material system (MS) causing a reflected generally vertically oriented propagation direction, polarized beam of electromagnetic radiation (LBO') to pass through said second focusing optic (F2) and interact with said second optic element (PRO), in which second optic element (PRO) said generally vertically oriented propagation direction, polarized beam of electromagnetic radiation (LBO') is, by essentially total internal reflection, caused to become a generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBO), which generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation then (LBO) then passes through analyzer (A) and, via an essentially circular shaped aperture (AP), enters said detector system (DET) for analysis, which generally vertically oriented propagation direction, polarized beams of electromagnetic radiation (LBI') and (LBO') approach and are reflected from, respectively, said material system (MS) at essentially equal angles of incidence and reflection ( ), as viewed in frontal elevation;
b. causing said light source (LS) and a polarizer (P), to produce a generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBI);
c. causing said generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBI) to interact with said first optic element (PRI) and by essentially total internal reflection therein become a generally vertically oriented propagation direction, polarized beam of electromagnetic radiation (LBI') which is caused to pass through a first focusing optic (F1) and interact with a material system (MS) placed upon said material system stage (MS);
d. causing a generally vertically oriented propagation direction, polarized beam of electromagnetic radiation (LBO') provided by said generally vertically oriented propagation direction, polarized beam of electromagnetic radiation (LBI') reflective interaction with said material system (MS) to pass through a second focusing optic (F2) and interact with a second optic element (PRO), in which second optic element (PRO) said generally vertically oriented propagation direction, polarized beam of electromagnetic radiation (LBO') is, by essentially total internal reflection, caused to become a generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBO);
e. causing said generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBO) to pass through said analyzer (A) and said aperture (AP) and enter detector system (DET);
wherein analysis of said generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBO) is performed.

15 more elements

A method of investigating a material system comprising the steps of:

a. providing a material system investigating system comprising:
a. a light source (LS);
b. a polarizer (P);
c. a first optic element (PRI);
d. a first focusing optic (F1);
e. a material system stage (STG);
f. a second focusing optic (F2);
g. a second optic element (PRO);
h. an analyzer (A);
i. a detector (DET);
and
j. optionally compensator(s) (C) (C');
said light source (LS) and polarizer (P), serving in use to produce a generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBI), said generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBI) being caused to interact with said first optic element (PRI) and by essentially total internal reflection therein become other than a generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBI') which is caused to pass through said first focusing optic (F1) and interact with a material system (MS) placed upon said material system stage (STG), said interaction with said material system (MS) causing a reflected other than generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBO') to pass through said second focusing optic (F2) and interact with said second optic element (PRO), in which second optic element (PRO) said generally other than horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBO') is, by essentially total internal reflection, caused to become a generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBO), which generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation then (LBO) then passes through analyzer (A) and, via an essentially circular shaped aperture (AP), enters said detector system (DET) for analysis, which generally other than horizontally oriented propagation direction, polarized beams of electromagnetic radiation (LBI') and (LBO') approach and are reflected from, respectively, said material system (MS) at essentially equal angles of incidence and reflection ( ), as viewed in frontal elevation;
b. causing said light source (LS) and a polarizer (P), to produce a generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBI);
c. causing said generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBI) to interact with said first optic element (PRI) and by essentially total internal reflection therein become other than a generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBI') which is caused to pass through a first focusing optic (F1) and interact with a material system (MS) placed upon said material system stage (MS);
d. causing an other than generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBO') provided by said other than a generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBI') reflective interaction with said material system (MS) to pass through a second focusing optic (F2) and interact with a second optic element (PRO), in which second optic element (PRO) said generally other than horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBO') is, by essentially total internal reflection, caused to become a generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBO);
e. causing said generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBO) to pass through said analyzer (A) and enter detector system (DET);
wherein analysis of said generally horizontally oriented propagation direction, polarized beam of electromagnetic radiation (LBO) is performed.

15 more elements

A material system investigating system comprising:

a. a light source (LS);
b. optionally a polarizer (P);
c. a first optic element (PRI);
d. a first focusing optic (F1);
e. a material system stage (STG);
f. a second focusing optic (F2);
g. a second optic element (PRO);
h. optionally an analyzer (A);
i. a detector (DET);
and
j. optionally compensator(s) (C) (C');
said light source (LS) serving in use to produce a generally horizontally oriented Propagation direction, beam of electromagnetic radiation (LBI), said generally horizontally oriented propagation direction, beam of electromagnetic radiation (LBI) being caused to interact with a first optic element (PRI) and, by essentially total internal reflection therein, become other than a generally horizontally oriented propagation direction, beam of electromagnetic radiation (LBI') which is caused to pass through a first focusing optic (F1) and reflectively interact with a material system (MS) placed upon said material system stage (STG), said reflective interaction with said material system (MS) causing an other than generally horizontally oriented propagation direction, beam of electromagnetic radiation (LBO') to pass through a second focusing optic (F2) and interact with a second optic element (PRO), in which second optic element (PRO) said generally other than horizontally oriented propagation direction, beam of electromagnetic radiation (LBO') is by essentially total internal reflection caused to become a generally horizontally oriented propagation direction, beam of electromagnetic radiation (LBO), which generally horizontally oriented propagation direction, beam of electromagnetic radiation (LBO) then via an essentially circular shaped aperture (AP), enters a detector system (DET) for analysis, which generally other than horizontally oriented propagation direction, beams of electromagnetic radiation (LBI') and (LBO') approach and are reflected from, respectively, said material system (MS) at essentially equal angles of incidence and reflection (.crclbar.), as viewed in frontal elevation.

9 more elements

A method of investigating a material system comprising the steps of:

a. providing a material system investigating system comprising:
a. a light source (LS);
b. optionally a polarizer (P);
c. a first optic element (PRI);
d. a first focusing optic (F1);
e. a material system stage (STG);
f. a second focusing optic (F2);
g. a second optic element (PRO);
h. optionally an analyzer (A);
i. a detector (DET);
and
j. optionally compensator(s) (C) (C');
said light source (LS) serving in use to produce a generally horizontally oriented propagation direction, beam of electromagnetic radiation (LBI), said generally horizontally oriented propagation direction, beam of electromagnetic radiation (LBI) being caused to interact with a first optic element (PRI) and, by essentially total internal reflection therein, become other than a generally horizontally oriented propagation direction, beam of electromagnetic radiation (LBI') which is caused to pass through a first focusing optic (F1) and reflectively interact with a material system (MS) placed upon said material system stage (STG), said reflective interaction with said material system (MS) causing an other than generally horizontally oriented propagation direction, beam of electromagnetic radiation (LBO') to pass through a second focusing optic (F2) and interact with a second optic element (PRO), in which second optic element (PRO) said generally other than horizontally oriented propagation direction, beam of electromagnetic radiation (LBO') is by essentially total internal reflection caused to become a generally horizontally oriented propagation direction, beam of electromagnetic radiation (LBO), which generally horizontally oriented propagation direction, beam of electromagnetic radiation (LBO) then via an essentially circular shaped aperture (AP), enters a detector system (DET) for analysis, which generally other than horizontally oriented propagation direction, beams of electromagnetic radiation (LBI') and (LBO') approach and are reflected from, respectively, said material system (MS) at essentially equal angles of incidence and reflection (.crclbar.), as viewed in frontal elevation;
b. causing said light source (LS) to produce a generally horizontally oriented propagation direction, beam of electromagnetic radiation (LBI);
c. causing said generally horizontally oriented propagation direction, beam of electromagnetic radiation (LBI) to interact with said first optic element (PRI) and by essentially total internal reflection therein become other than a generally horizontally oriented propagation direction, beam of electromagnetic radiation (LBI') which is caused to pass through a first focusing optic (F1) and reflectively interact with a material system (MS) placed upon said material system stage (MS);
d. causing an other than generally horizontally oriented propagation direction, beam of electromagnetic radiation (LBO') provided by said other than a generally horizontally oriented propagation direction, beam of electromagnetic radiation (LBI') reflective interaction with said material system (MS) to pass through a second focusing optic (F2) and interact with a second optic element (PRO), in which second optic element (PRO) said generally other than horizontally oriented propagation direction, beam of electromagnetic radiation (LBO') is, by essentially total internal reflection, caused to become a generally horizontally oriented propagation direction, beam of electromagnetic radiation (LBO);
e. causing said generally horizontally oriented propagation direction, beam of electromagnetic radiation (LBO) to pass through said aperture (AP) and enter detector system (DET);
wherein analysis of said generally horizontally oriented propagation direction, beam of electromagnetic radiation (LBO) is performed.

15 more elements

Dependencies are inferred from the claim text.