| abstract |
High purity hydroxy-terminated phenyl and alkenyl substituted ladder polysiloxane, which contains therein 1 ppm or below of each of sodium, potassium, iron, copper, lead and chloride, and 1 ppb or below of each of uranium and thorium, and is represented by the following general formula (I): ##STR1## where: R 1 is phenyl and R 2 is an alkenyl group; n is an integer of from 7 to 1600; m and l are natural numbers satisfying relationships of 2n=m+l and l/m+l≧0.02. n The high purity hydroxy-terminated ladder polysiloxane contains photosensitive groups in its side chain and is useful as a protective film and as an interlayer insulating film in the production of semiconductor elements. |