Control of residual stresses in as-grown polysilicon by multi-layer deposition: The "MultiPoly" process

Jie Yang, H. Kahn, A. Q. He, Stephen Phillips, A. H. Heuer

Research output: Chapter in Book/Report/Conference proceedingChapter

Abstract

LPCVD polysilicon thin films deposited between ∼550 and ∼600°C have an equiaxed microstructure (resulting from crystallization of an initially amorphous deposit) and contain ∼200 MPa residual tensile stresses after deposition, whereas polysilicon films deposited above ∼600°C have a columnar microstructure and contain ∼300 MPa residual compressive stresses after deposition. Both types of films also contain stress gradients. We have grown films containing multiple layers of polysilicon ("MultiPoly") by cycling the growth temperature between 570 and 615°C. The multilayer films thus formed are comprised of alternating tensile and compressive layers, and by control of the thickness of the individual layers, the overall stress of the polysilicon can display any value between that of the tensile layer and that of the compressive layer. We have focussed on producing films with zero overall residual stress, as measured by wafer curvature, and have characterized the microstructures by transmission electron microscopy (TEM) and X-ray diffraction (XRD). Because of the stress gradients present in both layers, devices made from films with zero overall residual stress may show distortions after release. We have measured the stress gradients in each type of layer and can design films with zero overall stress and zero overall stress gradients. It is also possible to design films with any level of overall (tensile or compressive) stress but with controlled displacements upon release.

Original languageEnglish (US)
Title of host publicationMaterials Research Society Symposium - Proceedings
Pages37-41
Number of pages5
Volume605
StatePublished - 2000
Externally publishedYes

Fingerprint

Polysilicon
Residual stresses
Compressive stress
Tensile stress
Microstructure
Multilayer films
Growth temperature
Crystallization
Deposits
Transmission electron microscopy
X ray diffraction
Thin films

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials

Cite this

Yang, J., Kahn, H., He, A. Q., Phillips, S., & Heuer, A. H. (2000). Control of residual stresses in as-grown polysilicon by multi-layer deposition: The "MultiPoly" process. In Materials Research Society Symposium - Proceedings (Vol. 605, pp. 37-41)

Control of residual stresses in as-grown polysilicon by multi-layer deposition : The "MultiPoly" process. / Yang, Jie; Kahn, H.; He, A. Q.; Phillips, Stephen; Heuer, A. H.

Materials Research Society Symposium - Proceedings. Vol. 605 2000. p. 37-41.

Research output: Chapter in Book/Report/Conference proceedingChapter

Yang, J, Kahn, H, He, AQ, Phillips, S & Heuer, AH 2000, Control of residual stresses in as-grown polysilicon by multi-layer deposition: The "MultiPoly" process. in Materials Research Society Symposium - Proceedings. vol. 605, pp. 37-41.
Yang J, Kahn H, He AQ, Phillips S, Heuer AH. Control of residual stresses in as-grown polysilicon by multi-layer deposition: The "MultiPoly" process. In Materials Research Society Symposium - Proceedings. Vol. 605. 2000. p. 37-41
Yang, Jie ; Kahn, H. ; He, A. Q. ; Phillips, Stephen ; Heuer, A. H. / Control of residual stresses in as-grown polysilicon by multi-layer deposition : The "MultiPoly" process. Materials Research Society Symposium - Proceedings. Vol. 605 2000. pp. 37-41
@inbook{283f5aebbc714127a4f3d71547ecc32f,
title = "Control of residual stresses in as-grown polysilicon by multi-layer deposition: The {"}MultiPoly{"} process",
abstract = "LPCVD polysilicon thin films deposited between ∼550 and ∼600°C have an equiaxed microstructure (resulting from crystallization of an initially amorphous deposit) and contain ∼200 MPa residual tensile stresses after deposition, whereas polysilicon films deposited above ∼600°C have a columnar microstructure and contain ∼300 MPa residual compressive stresses after deposition. Both types of films also contain stress gradients. We have grown films containing multiple layers of polysilicon ({"}MultiPoly{"}) by cycling the growth temperature between 570 and 615°C. The multilayer films thus formed are comprised of alternating tensile and compressive layers, and by control of the thickness of the individual layers, the overall stress of the polysilicon can display any value between that of the tensile layer and that of the compressive layer. We have focussed on producing films with zero overall residual stress, as measured by wafer curvature, and have characterized the microstructures by transmission electron microscopy (TEM) and X-ray diffraction (XRD). Because of the stress gradients present in both layers, devices made from films with zero overall residual stress may show distortions after release. We have measured the stress gradients in each type of layer and can design films with zero overall stress and zero overall stress gradients. It is also possible to design films with any level of overall (tensile or compressive) stress but with controlled displacements upon release.",
author = "Jie Yang and H. Kahn and He, {A. Q.} and Stephen Phillips and Heuer, {A. H.}",
year = "2000",
language = "English (US)",
volume = "605",
pages = "37--41",
booktitle = "Materials Research Society Symposium - Proceedings",

}

TY - CHAP

T1 - Control of residual stresses in as-grown polysilicon by multi-layer deposition

T2 - The "MultiPoly" process

AU - Yang, Jie

AU - Kahn, H.

AU - He, A. Q.

AU - Phillips, Stephen

AU - Heuer, A. H.

PY - 2000

Y1 - 2000

N2 - LPCVD polysilicon thin films deposited between ∼550 and ∼600°C have an equiaxed microstructure (resulting from crystallization of an initially amorphous deposit) and contain ∼200 MPa residual tensile stresses after deposition, whereas polysilicon films deposited above ∼600°C have a columnar microstructure and contain ∼300 MPa residual compressive stresses after deposition. Both types of films also contain stress gradients. We have grown films containing multiple layers of polysilicon ("MultiPoly") by cycling the growth temperature between 570 and 615°C. The multilayer films thus formed are comprised of alternating tensile and compressive layers, and by control of the thickness of the individual layers, the overall stress of the polysilicon can display any value between that of the tensile layer and that of the compressive layer. We have focussed on producing films with zero overall residual stress, as measured by wafer curvature, and have characterized the microstructures by transmission electron microscopy (TEM) and X-ray diffraction (XRD). Because of the stress gradients present in both layers, devices made from films with zero overall residual stress may show distortions after release. We have measured the stress gradients in each type of layer and can design films with zero overall stress and zero overall stress gradients. It is also possible to design films with any level of overall (tensile or compressive) stress but with controlled displacements upon release.

AB - LPCVD polysilicon thin films deposited between ∼550 and ∼600°C have an equiaxed microstructure (resulting from crystallization of an initially amorphous deposit) and contain ∼200 MPa residual tensile stresses after deposition, whereas polysilicon films deposited above ∼600°C have a columnar microstructure and contain ∼300 MPa residual compressive stresses after deposition. Both types of films also contain stress gradients. We have grown films containing multiple layers of polysilicon ("MultiPoly") by cycling the growth temperature between 570 and 615°C. The multilayer films thus formed are comprised of alternating tensile and compressive layers, and by control of the thickness of the individual layers, the overall stress of the polysilicon can display any value between that of the tensile layer and that of the compressive layer. We have focussed on producing films with zero overall residual stress, as measured by wafer curvature, and have characterized the microstructures by transmission electron microscopy (TEM) and X-ray diffraction (XRD). Because of the stress gradients present in both layers, devices made from films with zero overall residual stress may show distortions after release. We have measured the stress gradients in each type of layer and can design films with zero overall stress and zero overall stress gradients. It is also possible to design films with any level of overall (tensile or compressive) stress but with controlled displacements upon release.

UR - http://www.scopus.com/inward/record.url?scp=0034506848&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034506848&partnerID=8YFLogxK

M3 - Chapter

AN - SCOPUS:0034506848

VL - 605

SP - 37

EP - 41

BT - Materials Research Society Symposium - Proceedings

ER -