Influence of anneals in oxygen ambient on stress of thick polysilicon layers

Furtsch, M.; Offenberg, M.; Münzel, H.; Morante, J.R.

doi:10.1016/s0924-4247(98)00287-8

Cited by 14 publications

(6 citation statements)

References 16 publications

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“…(4) The main importance of the cantilevers is as an aide in understanding the flexures of other structures (e.g., the buckling direction of fixed-fixed beams, the curvature of microrings). (5) The strain measurements from the beam structures indicate that the strain state is different for polysilicon when grown on oxide versus polysilicon. The sensitive measurements enabled by the interferometry motivated us to find a microstructural difference in Poly2 on oxide versus on Poly1.…”

Section: Discussionmentioning

confidence: 99%

“…4The area required is 0.2 mm 2 per measurement ( Table 1). (5) Taking and analyzing the interferograms requires about 15 minutes per beam. Setting up for the FDM code run requires about ten minutes.…”

Section: Quantitative Evaluationmentioning

confidence: 99%

“…4The area requirements are large, 1.0 mm 2 per measurement ( Table 1). (5) Time to measure is about 15 minutes per structure. Analysis requires only a few minutes using Eq 1.…”

Section: Pointersmentioning

confidence: 99%

“…The assessment criteria, questions (1)- (5) from the Introduction, are considered in Table 4, in order of the experimental effectiveness of the test structures. In addition, we make further comments on each test structure in this section.Fixed-Fixed Beams-The fixed-fixed beams listed at the top of Table 4 yielded the highest resolution and most repeatable results.…”

Section: Assessment Of the Test Structuresmentioning

confidence: 99%

“…Polycrystalline silicon (polysilicon), used in integrated circuits and Microelectromechanical Systems (MEMS), is commonly deposited by chemical vapor deposition. Residual strain in polysilicon thin films is a result of the interactions of many factors that may be present during deposition, including thermal environments, dopants, impurities, and grain coalescence, orientation and growth, and surface as well as interfacial stress [1][2][3][4][5][6]. Because of the importance of residual strain in mechanical design and as a measure of fabrication control, many techniques and structures have been suggested for residual strain measurements.…”

Section: Introductionmentioning

confidence: 99%

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Side-by-Side Comparison of Passive MEMS Strain Test Structures under Residual Compression

Masters

Boer

Jensen

et al. 2001

Mechanical Properties of Structural Films

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Knowledge and control of residual strain is critical for device design in MEMS, and therefore it is important to establish standards for residual strain measurement. In this study, pointer, microring, bent-beam, and fixed-fixed beam test structures are used to evaluate residual strain both theoretically and experimentally. An equation that enables easier evaluation of bentbeam structures is derived. Also, a finite difference model that incorporates the non-idealities of fixed-fixed beams and determines an optimum fit to the measured deflection curve is presented. The model allows accurate residual strain evaluation of each buckled fixed-fixed beam. Experimentally, pointer structures were found to be susceptible to adhesion. Microrings, intended for residual tension assessment, also could not be evaluated because the residual strain was compressive. Bent-beam and fixed-fixed beams could both be evaluated. The main criterion for test structure effectiveness was taken to be the repeatability of residual strain on structures in close proximity; each should exhibit the same value. Using optical microscopy, the residual strain of bent-beams was determined with ± 13 µε repeatability based on standard deviation of adjacent structures of similar design. Using optical interferometry, the residual strain of fixed-fixed beams was determined with ± 2 µε repeatability based on standard deviation for adjacent beams of different lengths. The strain values obtained from the two structures are in reasonably good agreement. Cantilevers were also evaluated to obtain film curvature values.

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Section: Discussionmentioning

confidence: 99%

Section: Quantitative Evaluationmentioning

confidence: 99%

“…4The area requirements are large, 1.0 mm 2 per measurement ( Table 1). (5) Time to measure is about 15 minutes per structure. Analysis requires only a few minutes using Eq 1.…”

Section: Pointersmentioning

confidence: 99%

Section: Assessment Of the Test Structuresmentioning

confidence: 99%