A Phase Retrieval Method for Noncrystalline Layers on Crystal Surfaces

Abstract

A phase retrieval method for noncrystalline surface layers that involves intensity modulation of the specular reflection under the excitation of a Bragg reflection was applied to a Si(001) single crystal covered with a native oxide layer of a few nanometers thickness. The phases and moduli of the amplitudes of the scatterings from the native oxide layer were uniquely retrieved at three points on the specular truncation rod. The phases and moduli obtained experimentally were consistently explained by a model of a Si(001) single crystal covered with a uniform oxide layer with a rough surface.

Quantitative Analysis of the Strain Field beneath the Si₃N₄/Si(001) Interface Formed by the Xe/NH₃ Plasma Nitridation using a Multiple-Wave X-ray Diffraction Phenomenon

“…Note that the rocking curves of the 004 Bragg reflection were explained by a perfect crystal. These facts support the idea that a very small and long-range strain field is induced by the NH radical nitridation, the depth of which is sufficiently small compared with the extinction depth of the 004 Bragg reflection [2]. The phase difference's dependence on Δl suggests that the lattice spacing in the strain field is not constant.…”

“…1) [1][2][3][4]. We define the surface unit cell vectors a s1 , a s2 , and a s3 by a s1 = a 1 / 2 + a 2 / 2 , -a 1 / 2 + a 2 / 2 , and a 3 , where a 1 , a 2 , and a 3 are the unit cell vectors of the diamond cubic structure of Si.…”

“…This is true even in the case of the silicon dioxide-silicon interface, which has been applied to electronic devices since the 1960s. In previous papers [1][2][3][4][5], we have investigated strain fields beneath the SiO 2 /Si interfaces using a multiple X-ray diffraction phenomenon, which is modulation of the crystal-truncation-rod (CTR) scattering intensity under a Bragg reflection [6][7][8][9][10][11]. Using this technique has revealed that there is a very small strain field beneath the SiO 2 /Si interface whose depth extends up to several tens of nanometers and has a static fluctuation in the lateral direction.…”

“…Using this technique has revealed that there is a very small strain field beneath the SiO 2 /Si interface whose depth extends up to several tens of nanometers and has a static fluctuation in the lateral direction. Information on the depth profile of the strain has been also qualitatively obtained using this technique [2,3,5]. In this paper we present a master formula for the CTR scattering from a crystal with strain, and attempt to quantitatively analyze the strain field beneath the Si 3 N 4 /Si(001) interface formed by the high-density Xe/NH 3 plasma using this technique.…”

Study of the Interface Structure of Epitaxial Ultra-Thin Film by an X-Ray Holographic Imaging Method

“…It should be mentioned that a number of studies have been done to solve the surface structure using various kinds of direct methods [17][18][19][20][21][22][23][24][25][26][27], but most of them are underway. At the present stage we think that such direct methods are much helpful to distinguish the most probable model from others.…”