Global to push GA events into
skip to main content

Title: Recrystallization method to selenization of thin-film Cu(In,Ga)Se.sub.2 for semiconductor device applications

A process for fabricating slightly Cu-poor thin-films of Cu(In,Ga)Se.sub.2 on a substrate for semiconductor device applications includes the steps of forming initially a slightly Cu-rich, phase separated, mixture of Cu(In,Ga)Se.sub.2 :Cu.sub.x Se on the substrate in solid form followed by exposure of the Cu(In,Ga)Se.sub.2 :Cu.sub.x Se solid mixture to an overpressure of Se vapor and (In,Ga) vapor for deposition on the Cu(In,Ga)Se.sub.2 :Cu.sub.x Se solid mixture while simultaneously increasing the temperature of the solid mixture toward a recrystallization temperature (about 550.degree. C.) at which Cu(In,Ga)Se.sub.2 is solid and Cu.sub.x Se is liquid. The (In,Ga) flux is terminated while the Se overpressure flux and the recrystallization temperature are maintained to recrystallize the Cu.sub.x Se with the (In, Ga) that was deposited during the temperature transition and with the Se vapor to form the thin-film of slightly Cu-poor Cu.sub.x (In,Ga).sub.y Se.sub.z. The initial Cu-rich, phase separated large grain mixture of Cu(In,Ga)Se.sub.2 :Cu.sub.x Se can be made by sequentially depositing or co-depositing the metal precursors, Cu and (In, Ga), on the substrate at room temperature, ramping up the thin-film temperature in the presence of Se overpressure to a moderate anneal temperature (about 450.degree. C.) and holding that temperature and the Se overpressure formore » an annealing period. A nonselenizing, low temperature anneal at about 100.degree. C. can also be used to homogenize the precursors on the substrates before the selenizing, moderate temperature anneal.« less
Inventors:
 [1];  [2];  [1];  [3];  [4];  [3];  [1]
  1. (Denver, CO)
  2. (Evergreen, CO)
  3. (Golden, CO)
  4. (Boulder, CO)
Issue Date:
OSTI Identifier:
870002
Assignee:
Midwest Research Institute (Kansas City, MO) ANL
Patent Number(s):
US 5436204
Application Number:
08/293,826
Research Org:
Argonne National Laboratory (ANL), Argonne, IL
Country of Publication:
United States
Language:
English
Subject:
recrystallization; method; selenization; thin-film; cu; semiconductor; device; applications; process; fabricating; slightly; cu-poor; thin-films; substrate; steps; forming; initially; cu-rich; phase; separated; mixture; solid; form; followed; exposure; overpressure; vapor; deposition; simultaneously; increasing; temperature; 550; degree; liquid; flux; terminated; maintained; recrystallize; deposited; transition; z; initial; grain; sequentially; depositing; co-depositing; metal; precursors; ramping; presence; moderate; anneal; 450; holding; annealing; period; nonselenizing; 100; homogenize; substrates; selenizing; slightly cu-poor; phase separated; metal precursor; film temperature; solid form; device applications; semiconductor device; solid mixture; moderate temperature; recrystallization temperature; temperature anneal; rate temperature; metal precursors; phase separate; /438/117/136/