Abstract:
Alignment of layers during manufacture of a multi-layer sample is controlled by applying optical measurements to a measurement site in the sample. The measurement site includes two diffractive structures located one above the other in two different layers, respectively. The optical measurements comprise at least two measurements with different polarization states of incident light, each measurement including illuminating eh measurement site so as to illuminate one of the diffractive structures through the other. The diffraction properties of the measurement site are indicative of a lateral shift between eth diffractive structures. The diffraction properties detected are analyzed for the different polarization states of the incident light to determine an existing lateral shift between the layers.
Abstract:
The method for controlling layers alignment in a multi-layer sample (10), such a semiconductors wafer based on detecting a diffraction efficiency of radiation diffracted from the patterned structures (12, 14) located one above the other in two different layers of the sample.
Abstract:
A method and system are presented for use in optical processing of an article by VUV radiation. The method comprises: localizing incident VUV radiation propagation from an optical head assembly towards a processing site on the article outside the optical head assembly and localizing reflected VUV radiation propagation from said processing site towards the optical head assembly by localizing a medium, non-absorbing with respect to VUV radiation, in within the light propagation path in the vicinity of said site outside the optical head assembly.
Abstract:
An optical measurement method and system are presented for imaging two target structures in two parallel layers, respectively, of a sample, to enable determination of a registration between the two target structures along two mutually perpendicular axes of the layer. The sample is illuminated with incident radiation to produce a radiation response of the sample. The radiation response is collected by an objective lens arrangement, and the collected radiation response is split into two spatially separated radiation components. The split radiation components are directed towards at least one imaging plane along different optical channels characterized by optical paths of different lengths, respectively. The two split radiation components are detected in said at least one imaging plane, and two image parts are thereby acquired, each image part containing images of the two target structures. This enables determination of the relative distance between the two target structures.
Abstract:
A method is presented for optical control of the quality of a process of chemical mechanical planarization (CMP) performed by a polishing tool applied to an article having a patterned area. The article contains a plurality of stacks each formed by a plurality of different layers, thereby defining a pattern in the form of spaced-apart metal regions. The method is capable of locating at least one of residues, erosion and dishing conditions on the article. At least one predetermined site on the article is selected for control. This at least one predetermined site is illuminated, and spectral characteristics of light components reflected from this location are detected. Data representative of the detected light components is analyzed for determining at least one parameter of the article within the at least one illuminated site.
Abstract:
A method for measuring at least one desired parameter of a patterned structure having a plurality of features defined by a certain process of its manufacturing. The structure represents a grid having at least one cycle formed of at least two locally adjacent elements having different optical properties in respect of an incident radiation. An optical model, based on at lease some of the features of the structure is provided. The model is capable of determining theoretical data representative of photometric intensities of light components of different wavelengths specularly reflected from the structure and of calculating said at least one desired parameter of the structure. A measurement area, which is substantially larger than a surface area of the structure defined by the grid cycle, is illuminated by an incident radiation of a preset substantially wide wavelength range. Light component substantially specularly reflected from the measurement area is detected and measured data representative of photometric intensities of each wavelength within the wavelength range is obtained. The measured and theoretical data satisfies a predetermined condition. Upon detecting that the predetermined condition is satisfied, said at least one parameter of the structure is calculated.
Abstract:
An autofocussing mechanism is provided which is useful for all objective lenses and during scanning of the object. The autofocussing mechanism operates with a microscope having a main optical path, an objective lens, an object surface, an image plane and apparatus for changing the distance between the objective lens and the object surface thereby to focus the image of the object. The autofocussing mechanism preferably includes a pattern imaging system, a single image detector and a pattern focus analyzer. The pattern imaging system images at least one pattern through the objective lens along the main optical path and onto the object surface. The image of the pattern is then combined with an image of the object and is reflected along the main optical path towards the image plane. The image detector detects the reflected image and the pattern focus analyzer determines the extent of sharpness of the pattern by analyzing the output of the image detector. The pattern focus analyzer can also indicate, to the apparatus for changing the distance, to move in a direction of increased focus.
Abstract:
A method and system are provided for controlling processing of a structure. First measured data is provided being indicative of at least one of: a thickness (d2) of at least one layer (L2) of the structure W in at least selected sites of the structure prior to processing of the structure, and a surface profile of the structure prior to processing. An optical measurement is applied to at least the selected sites of the structure after processing and second measured data is generated being indicative of at least one of: a thickness of the processed structure (d′) and a surface profile of the processed structure. The second measured data is analyzed by interpreting it using the first measured data to determine a thickness (d′1 or d′2) of at least one layer of the processed structure. This determined thickness is indicative of the quality of processing.
Abstract:
A system and method for use in spectrometric measurements of an article using selecting an optimal integration time range of the light detection system during which the measurement is to be applied, the optimal integration time being that at which a required value of signal to noise ratio (SNR) of the measurements is obtainable.
Abstract:
A photovoltaic cell, the cell comprising: a silicon substrate of bulk silicon material having front and rear surfaces; an emitter layer on the rear surface of said substrate; elongate channels through the emitter layer; elongate contacts to the bulk of the silicon substrate within at least some of the elongate channels, wherein the contacts are narrower than the channels; and gaps in the emitter between at least some of the elongate contacts and the emitter layer on the sides of the contacts.