Optical microresonators have recently attracted growing attention in the photonics community1. Their applications range from quantum electrodynamics to sensors and filtering devices for optical telecommunication systems, where they will probably become an essential building block2. Integration of nonlinear and electro–optical properties in resonators represents a very stimulating challenge, as it would incorporate new and more advanced functionality. Lithium niobate is an excellent candidate material, being an established choice for electro–optic and nonlinear optical applications. Here we report on the first realization of optical microring resonators in submicrometre thin films of lithium niobate. High-index-contrast films are produced by an improved crystal-ion-slicing and bonding technique using benzocyclobutene. The rings have radius R = 100 µm, and their transmission spectrum has been tuned using the electro–optic effect. These results open new possibilities for the use of lithium niobate in chip-scale integrated optical devices and nonlinear optical microcavities.

Electro–optically tunable microring resonators in lithium niobate

The state-of-the-art of high-refractive-index-contrast single-crystalline thin lithium niobate (LiNbO3) films as a new platform for high-density integrated optics is reviewed. Sub-micrometer thin LiNbO3 films are obtained by “ion-slicing”. They can be bonded by two different techniques to a low-index substrate to obtain “lithium niobate on insulator” (LNOI) even as wafer of 3” diameter. Different micro- and nano-structuring techniques have been used to successfully develop micro-photonic devices. To be specific, the fabrication and characterization of LNOI photonic wires with cross-section < 1 µm2, periodically poled LNOI photonic wires for second harmonic generation, electro-optically tunable microring resonators, free standing microrings for hybrid integration, and photonic crystal structures are described.

Lithium niobate on insulator (LNOI) for micro-photonic devices

▪ Abstract As integrated circuit (IC) dimensions continue to decrease, RC delay, crosstalk noise, and power dissipation of the interconnect structure become limiting factors for ultra-large-scale integration of integrated circuits. Materials with low dielectric constant are being developed to replace silicon dioxide as interlevel dielectrics. In this review, the general requirements for process integration and material properties of low-k dielectrics are first discussed. The discussion is focused on the challenge in developing materials with low dielectric constant but strong thermomechanical properties. This is followed by a description of the material characterization techniques, including several recently developed for porous materials. Finally, the material characteristics of candidate low-k dielectrics will be discussed to illustrate their structure-property relations.

Low Dielectric Constant Materials for ULSI Interconnects

Copper interconnections and reliability

Single-mode optical waveguides at 1300 nm have been fabricated from the organic polymer benzocyclobutene. This material system utilizes a 535 rmb photodefinable resin for forming the core of the waveguide, allowing the waveguides to be processed in a fashion similar to a negative photoresist. The processing conditions required for the fabrication of single-mode benzocyclobutene optical waveguides are presented. With the measured losses in the waveguide equal to 0.81 dB/cm at 1300 nm, this material system is suitable for use in a variety of optical interconnect applications. >

http://users.rowan.edu/~krchnavek/rowan_university/research-pubs_files/ptl_7_may_95.pdf

Benzocyclobutene optical waveguides

A new class of organic dielectrics, benzocyclobutenes, 1, are described and their application to the fabrication of thin film multichip modules is detailed. Key properties for3, a siloxy containing BCB derivative include low dielectric constant (2.7), low loss (0.008 at 1 MHz), low water absorption (0.25% after 24 h water boil) and high degree of planarization (>90% from one layer coverage). All other properties meet the requirements necessary for fabrication of thin film MCM structures.

Benzocyclobutene (BCB) dielectrics for the fabrication of high density, thin film multichip modules

A new class of organic dielectrics, benzocyclobutenes, 1, are described and their application to the fabrication of thin film multichip modules is detailed. Key properties for 3, a siloxy containing BCB derivative include low dielectric constant (2.7), low loss (0.008 at 1 MHz), low water absorption (0.25% after 24 h water boil) and high degree of planarization (>90% from one layer coverage). All other properties meet the requirements necessary for fabrication of thin film MCM structures.

Benzocyclobutene (BCB) Dielectrics for the High Density, Thin Film Multichip Modules Fabrication of

Multilayer interconnection structures incorporating a novel polymeric dielectric derived from a bis-benzocyclobutene(bis-BCB) monomer have been fabricated. This paper discusses the processing conditions for the construction of these circuits and describes electrical characteristics of the dielectric layers. The relative dielectric constant of the BCB film was 2.7. Thermal cycling produced no significant change in the conductance of three level metal via chains through two layers of the polymer.

The Processing and Properties of Multilayer Interconnection Structures Using Thermoset Films Derived from Bisbenzocyclobutene.

A method for determining the configuration of a resin portion of an article comprising exposing the article to a light source at a first wavelength and measuring emission of light at a second, different wavelength; wherein the resin contains a moiety containing a structure of the formula: ##STR1## or a moiety which is a reaction product of said moiety in a quantity sufficient to impart fluorescent properties to said resin.

Joseph Carr

Papers

Benzocyclobutene (BCB) dielectrics for the fabrication of high density, thin film multichip modules

Benzocyclobutene (BCB) Dielectrics for the High Density, Thin Film Multichip Modules Fabrication of

The Processing and Properties of Multilayer Interconnection Structures Using Thermoset Films Derived from Bisbenzocyclobutene.

Method of optical inspection