In the mid-1960s, RCA began development of VideoDiscs, aiming to revolutionize home entertainment. Similar to record albums, the VideoDisc was a grooved vinyl platter played with a stylus. However, unlike records, it carried both audio and video at a higher density, using an electrical stylus. It is often confused with the Laserdisc, which used an optical laser.

RCA branded its system Capacitance Electronic Discs (CED). The player spun the 30-centimeter disc at 450 rpm. A metallic stylus followed the grooves, detecting capacitance differences caused by depressions and bumps, much like a touchscreen detects finger contact. Solid-state circuits decoded the frequency-modulated video signal from these capacitance variations. These minute differences, measured in femtofarads, and the high-frequency video signal (around 910 megahertz) demanded highly sensitive capacitance sensors for a clear picture.

However, commercialization faced significant delays. RCA initially announced a 1973 debut, which never happened.A 1977 popular Science article predicted regional sales by year’s end, but the RCA SelectaVision system didn’t launch until March 1981. Despite ample marketing efforts, it performed poorly and was discontinued in 1984. RCA invested approximately US $500 million over two decades in the VideoDisc,only to see it fail.

Videotape’s Victory over VideoDisc

“Despite heavy promotion, it sold poorly and was pulled from the shelves in 1984.”

The primary reason for its failure: videotape. RCA had dismissed magnetic tape, but it proved more appealing to consumers. VHS tapes, introduced in 1976, were cheaper, offered a wider selection of titles for purchase or rental, and allowed users to record their own content.

A 1973 launch might have given the VideoDisc a chance,but technological challenges persisted. Early designs were vulnerable to fingerprints, dust, and scratches, requiring users to handle discs in protective shells. The final version encased the discs in plastic shells that were inserted into the player.

Running time was another limitation. in 1977, VideoDiscs held only 30 minutes per side, increasing to an hour by launch. Movies exceeding 120 minutes required multiple discs. The initial VHS tapes offered 120 minutes, double that of Betamax, and later versions provided long play (four hours) and extended play (six hours), albeit with reduced resolution.

RCA’s pricing forecasts were also inaccurate. they estimated a $500 VideoDisc player in 1977 (approximately $2,800 today).While early VHS players cost $1,000 to $1,400, prices dropped to $200-$400 by the mid-1980s.VHS tapes of major films cost around $80, significantly more than VideoDiscs’ $10-$18. However, rental companies emerged, offering movies for a small fee. RCA VideoDiscs briefly appeared alongside videotapes,but with fewer titles.

RCA struggled to sell its players. They projected annual sales of five to six million, with a first-year goal of 200,000, but sold only half that number. By 1984, RCA abandoned the VideoDisc, recognizing its lack of profitability.

the Birth of the Scanning Capacitance Microscope

The VideoDisc story could have ended there, as just another failed consumer electronics venture.However, RCA scientists needed microscopes capable of identifying the minute variations encoding the audio/video signal. The bumps and depressions were less than a tenth the size of the groove itself, beyond the resolution of existing microscopes.

RCA’s James matey developed the scanning capacitance microscope (SCM) for VideoDisc quality control.After the initial patent, RCA filed a reissue patent with corrections and improvements. In the March 1985 issue of the Journal of Applied Physics, Matey and Joseph Blanc detailed the technology. The SCM detected surface topography variations of 0.3 nanometers over 0.5 square micrometers. RCA delayed publication until after shuttering the videodisc operation. Matey and Blanc concluded, “We are currently in the process of adapting [the SCM] for similar uses on other samples.” The new application was in semiconductor manufacturing.

Semiconductor performance relies on the distribution of dopants, intentionally introduced impurities that alter electrical conductivity. Early semiconductor production used ion mass spectroscopy and spreading resistance to measure dopant distribution in one dimension.

By the late 1980s, integrated circuits required two-dimensional dopant measurement. The SCM, combined with an atomic force microscope, provided this capability. The conductive tip created a small capacitance,depending on dopant concentration. The SCM measured capacitance changes and mapped dopant distributions. NIST researchers validated the technology.

In the early 1990s, Joseph Kopanski, Jay Marchiando, and David Berning built custom SCMs at NIST, providing models and software for extracting two-dimensional dopant distribution from capacitance measurements.

NIST’s validation led to commercial SCM production, enabling the development of advanced semiconductors. This industry is far more significant to the global economy than the VideoDisc ever could have been. It’s a story of technological redemption: even in failure, innovation can emerge.