Silicon-containing positive photoresists

Alkali-developable silicon-containing positive photoresists, development, 175 Alkoxysilanes, polymerization,... 

A Silicon-Containing Positive Photoresist Developable with Aqueous Alkaline Solution... 

We have developed a silicon containing positive photoresist in the same manner that we developed an iodine containing resist previously. In other words, silicon compounds are blended into a conventional positive photoresist. 

The new silicon containing positive photoresists which consist of silicon compounds and a commercially available positive resist, OFPR-800, were evaluated as the top imaging layer in a two-level resist system. We sought silicon compounds specified by the following restrictions. 

Many kinds of silicon-containing photoresists have been reported(6-11) to have both O2 RIE resistance and high resolution. Among them a positive photoresist called ASTRO( ), a mixture of conventional positive photoresist and a silicon resin developed by Hitachi for the imaging layer of bi-level resist system, was selected as an etching mask in this experiment for the following reasons. First its... 

The difference of the amount of scum among the samples is clearly explained assuming the scum to be silicon oxide produced by the reaction of oxygen and silicon atom. The difference of the amount of scum in Figures 6a and 6c comes from the different concentration of silicon contained in X-8000K2 and conventional positive photoresist. The amount of scum observed in Figure 5 is the... 

Couillard and Craighead (1994) showed that direct application of positive photoresist could be achieved on a thick layer of macroporous sihcon and that the photoresist pattern could subsequently be transferred via an O2 plasma etch. The photoresist was developed in a basic solvent (tetramethylammonium hydroxide or TMAH). These developers rapidly dissolve high-porosity microporous silicon features however, PS formed from lightly doped n-type Si can survive this treatment. Positive photoresists and alkaline developers (typically containing metal ions such as potassium borate) can be used directly on PS if the surface is first partially oxidized by exposure to ozone. Features of 500 pm diameter were fabricated in this manner on a 60-cycle ruggate filter on... 

Soluble polydiorganosilane homo and copolymers have recently shown great potential in such areas as precursors for the preparation of silicon carbide fibers (1), as photoinitiators in alkene polymerization (2), as photoconductors (3), and as positive or negative self-developing photoresists for photolithographic applications (4). A number of copolydiorganosilane copolymers have been reported recently (5) in which the copolymer contained equal amounts of both monomers in the feed. 

Both negative and positive acting, oxygen RIE resistnt e-beam resist systems have been prepared through the incorporation of the trimethylsilylmethyl functionality into standard resist chemistry. Resins containing >10 wt% silicon display an RIE resistance more than 10 times greater than conventional photoresists and allow submicron pattern transfer with minimum linewidth loss. 

A transparency containing the channel design produced from a computer drawing is used as a photomask to produce a positive pattern of the channels in photoresist on a silicon wafer. 

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