EXHIBIT 99.1

Unaudited Pro Forma Combined Financial Information

as of and for the fiscal year ended August 28, 1999


FSI International, Inc. and Subsidiaries and YieldUP
International Corporation

The following unaudited pro forma combined financial information
presents the pro forma effect of the acquisition of YieldUP
International Corporation (YieldUP) by FSI
International, Inc. (FSI) on FSIs historical
financial position and results of operations using the purchase
method of accounting. YieldUPs fiscal year ends
December 31. In presenting the combination on a pro forma
basis, YieldUPs statement of operations for the year ended
September 30, 1999 was combined with FSIs statement of
 operations for the year ended August 28, 1999. The pro forma
combined financial information should be read in conjunction with
 the historical financial information of FSI and YieldUP included
 in FSIs registration statement on Form S-4 (File
No. 333-87003) and are hereby incorporated by reference. The
 pro forma combined financial information has been prepared and
included as required by the rules and regulations of the SEC and
does not purport to be indicative of the results that actually
would have been obtained if the acquisition had been effected on
the dates indicated or of the results that may be obtained in the
 future.

6



---



FSI INTERNATIONAL, INC. AND SUBSIDIARIES

AND YIELDUP INTERNATIONAL CORPORATION


UNAUDITED PROFORMA

COMBINED STATEMENT OF OPERATIONS


|                                                                                    |                                                                                    |               |             |               |   |             |            |            |   |  |           |            |      |   |             |             |  
|----------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------- | ------------- | ----------- | ------------- | - | ----------- | ---------- | ---------- | - |  | --------- | ---------- | ---- | - | ----------- | ----------- | -
|                                                                                    |                                                                                    |               |             |               |   |            
|                                                                                    |                                                                                    | Historical    |             |               |   |            
|                                                                                    |                                                                                    |               |             |               |   |            
|                                                                                    |                                                                                    | FSI           |             | YieldUP       |   |             |            |           
|                                                                                    |                                                                                    | International |             | International |   |             |            | Pro Forma 
|                                                                                    |                                                                                    | Inc.          |             | Corporation   |   |             |            | Combined  
|                                                                                    |                                                                                    | Year ended    |             | Year ended    |   |             |            | Year ended
|                                                                                    |                                                                                    | August 28,    |             | September 30, |   | Pro Forma   |            | August 28,
|                                                                                    |                                                                                    | 1999          |             | 1999          |   | Adjustments |            | 1999      
|                                                                                    |                                                                                    |               |             |               |   |             |            |           
|Sales                                                                               |                                                                                    | $             | 113,512,360 |               |   | $           | 5,499,463  |            |   |  |           |            |      | $ | 119,011,823 |            
|                                                                                   
|                                                                                   
|                                                                                   
|                                                                                   
|Cost of goods sold                                                                  |                                                                                    |               | 78,700,362  |               |   |             | 5,064,412  |            |   |  |           |            |      |   | 83,764,774  |            
|                                                                                    |                                                                                    |               |             |               |   |             |            |            |   |  |           |            |      |   |             |            
|                                                                                    | Gross Profit                                                                       |               |             | 34,811,998    |   |             |            | 435,051    |   |  |           |            |      |   |             | 35,247,049  |  
|                                                                                   
|                                                                                   
|                                                                                   
|                                                                                   
|Selling, general and administrative expenses                                        |                                                                                    |               | 37,263,717  |               |   |             | 3,511,356  |            |   |  | 1,276,000 | (e)        |      |   | 42,051,073  |            
|                                                                                   
|                                                                                   
|                                                                                   
|                                                                                   
|Research and development expenses                                                   |                                                                                    |               | 31,592,243  |               |   |             | 2,213,429  |            |   |  | 2,266,000 | (e)        |      |   | 36,071,672  |            
|                                                                                    |                                                                                    |               |             |               |   |             |            |            |   |  |           |            |      |   |             |            
|                                                                                    | Operating loss                                                                     |               |             | (34,043,962   | ) |             |            | (5,289,734 | ) |  |           |            |      |   |             | (42,875,696 | )
|                                                                                   
|                                                                                   
|                                                                                   
|                                                                                   
|Interest expense                                                                    |                                                                                    |               | (3,766,883  | )             |   |             | (152,653   | )          |   |  |           |            |      |   | (3,919,536  | )          
|                                                                                   
|                                                                                   
|                                                                                   
|                                                                                   
|Interest income                                                                     |                                                                                    |               | 4,630,156   |               |   |             | 75,066     |            |   |  | (364,000  | )(f)       |      |   | 4,341,222   |            
|                                                                                   
|                                                                                   
|                                                                                   
|                                                                                   
|Other expense, net                                                                  |                                                                                    |               | 72,895      |               |   |             |           |            |   |  |           |            |      |   | 72,895      |            
|                                                                                    |                                                                                    |               |             |               |   |             |            |            |   |  |           |            |      |   |             |            
|                                                                                    | Loss before income taxes                                                           |               |             | (33,107,794   | ) |             |            | (5,367,321 | ) |  |           |            |      |   |             | (42,381,115 | )
|                                                                                   
|                                                                                   
|                                                                                   
|                                                                                   
|Income tax expense                                                                  |                                                                                    |               | 5,844,990   |               |   |             |           |            |   |  |           |            |      |   | 5,844,990   |            
|                                                                                    |                                                                                    |               |             |               |   |             |            |            |   |  |           |            |      |   |             |            
|Loss before minority interest and equity in earnings of
	affiliates                 |                                                                                    |               | (38,952,784 | )             |   |             | (5,367,321 | )          |   |  |           |            |      |   | (48,226,105 | )          
|                                                                                   
|                                                                                   
|                                                                                   
|                                                                                   
|Equity in losses of affiliates                                                      |                                                                                    |               | (1,165,931  | )             |   |             |           |            |   |  |           |            |      |   | (1,165,931  | )          
|                                                                                    |                                                                                    |               |             |               |   |             |            |            |   |  |           |            |      |   |             |            
|                                                                                    | Net loss from continuing operations                                                |               |             | (40,118,715   | ) |             |            | (5,367,321 | ) |  |           |            |      |   |             | (49,392,036 | )
|                                                                                   
|                                                                                   
|                                                                                   
|                                                                                   
|Discontinued operations:                                                            |                                                                                    |               |             |               |   |             |            |            |   |  |           |            |      |   |             |            
|                                                                                   
|                                                                                   
|                                                                                   
|                                                                                   
|                                                                                    | Net loss from discontinued operations                                              |               |             | (6,422,864    | ) |             |            |           |   |  |           |            |      |   |             | (6,422,864  | )
|                                                                                   
|                                                                                   
|                                                                                   
|                                                                                   
|                                                                                    | Gain on sale of net assets of discontinued operations, net of
	$8,886,000 of taxes |               |             | 15,907,271    |   |             |            |           |   |  |           |            |      |   |             | 15,907,271  |  
|                                                                                    |                                                                                    |               |             |               |   |             |            |            |   |  |           |            |      |   |             |            
|Net loss                                                                            |                                                                                    | $             | (30,634,308 | )             |   | $           | (5,367,321 | )          |   |  |           |            |      | $ | (39,907,629 | )          
|                                                                                    |                                                                                    |               |             |               |   |             |            |            |   |  |           |            |      |   |             |            
|Net (loss) income per common share  Basic and
	Fully Diluted Continuing operations |                                                                                    | $             | (1.73       | )             |   | $           | (0.67      | )          |   |  |           |            |      | $ | (2.02       | )          
|                                                                                   
|                                                                                   
|                                                                                   
|                                                                                   
|                                                                                    | Discontinued operations                                                            |               |             | 0.41          |   |             |            |           |   |  |           |            |      |   |             | 0.39        |  
|                                                                                    |                                                                                    |               |             |               |   |             |            |            |   |  |           |            |      |   |             |            
|                                                                                    | Net loss                                                                           |               | $           | (1.32         | ) |             | $          | (0.67      | ) |  |           |            |      |   | $           | (1.63       | )
|                                                                                    |                                                                                    |               |             |               |   |             |            |            |   |  |           |            |      |   |             |            
|                                                                                    | Weighted average common shares                                                     |               |             | 23,204,706    |   |             |            | 7,974,270  |   |  |           | (7,974,270 | )(i) |   |             | 24,508,092  |  
|                                                                                    |                                                                                    |               |             |               |   |             |            |            |   |  | 1,303,386 | (i)        |      |   |             |            
|                                                                                   
|                                                                                   
|                                                                                   
|                                                                                   
|                                                                                    | Weighted average common and potential common shares                                |               |             | 23,204,706    |   |             |            | 7,974,270  |   |  |           | (7,974,270 | )(i) |   |             | 24,508,092  |  
|                                                                                    |                                                                                    |               |             |               |   |             |            |            |   |  | 1,303,386 | (i)        |      |   |             |            

7



---



FSI INTERNATIONAL, INC. AND SUBSIDIARIES

AND YIELDUP INTERNATIONAL CORPORATION


UNAUDITED PROFORMA

COMBINED BALANCE SHEET


|                                        |                                                  |                           |                            |               |             |             |           |             |           |            |            |             |      |   |             |             |             |             | 
|--------------------------------------- | ------------------------------------------------ | ------------------------- | -------------------------- | ------------- | ----------- | ----------- | --------- | ----------- | --------- | ---------- | ---------- | ----------- | ---- | - | ----------- | ----------- | ----------- | ----------- | 
|                                        |                                                  |                           |                            |               |             |            
|                                        |                                                  | Historical                |                            |               |             |            
|                                        |                                                  |                           |                            |               |             |            
|                                        |                                                  | FSI                       |                            | YieldUP       |             |             |           |            
|                                        |                                                  | International             |                            | International |             |             |           | Pro Forma  
|                                        |                                                  | Inc.                      |                            | Corporation   |             |             |           | Combined   
|                                        |                                                  | August 28,                |                            | September 30, |             | Pro Forma   |           | August 28, 
|                                        |                                                  | 1999                      |                            | 1999          |             | Adjustments |           | 1999       
|                                        |                                                  |                           |                            |               |             |             |           |            
|Current assets:                         |                                                  |                           |                            |               |             |             |           |             |           |            |            |             |      |   |             |            
|                                       
|                                       
|                                       
|                                       
|                                        | Cash, cash equivalents and marketable securities |                           | $                          | 89,998,008    |             |             | $         | 561,690     |           |            | $          | (6,713,000  | )(c) |   | $           | 83,846,698  |            
|                                       
|                                       
|                                       
|                                       
|                                        | Trade accounts receivable, net                   |                           |                            | 17,662,389    |             |             |           | 550,176     |           |            |            |             |      |   |             | 18,212,565  |            
|                                       
|                                       
|                                       
|                                       
|                                        | Trade accounts receivable from affiliates        |                           |                            | 12,659,778    |             |             |           |            |           |            |            |             |      |   |             | 12,659,778  |            
|                                       
|                                       
|                                       
|                                       
|                                        | Inventories                                      |                           |                            | 32,911,669    |             |             |           | 2,232,473   |           |            |            | 2,245,000   | (b)  |   |             | 37,389,142  |            
|                                       
|                                       
|                                       
|                                       
|                                        | Refundable income taxes                          |                           |                            | 160,915       |             |             |           |            |           |            |            |             |      |   |             | 160,915     |            
|                                       
|                                       
|                                       
|                                       
|                                        | Other current assets                             |                           |                            | 5,568,093     |             |             |           | 3,000       |           |            |            |             |      |   |             | 5,571,093   |            
|                                        |                                                  |                           |                            |               |             |             |           |             |           |            |            |             |      |   |             |            
|                                        |                                                  | Total current assets      |                            |               | 158,960,852 |             |           |             | 3,347,339 |            |            |             |      |   |             |             | 157,840,191 |            
|                                       
|                                       
|                                       
|                                       
|Property, plant and equipment, net      |                                                  |                           | 64,091,223                 |               |             |             | 1,221,967 |             |           |            |            |             |      |   | 65,313,190  |            
|                                       
|                                       
|                                       
|                                       
|Intangibles                             |                                                  |                           |                           |               |             |             | 227,037   |             |           |            | 18,530,136 | (a)         |      |   | 18,757,173  |            
|                                       
|                                       
|                                       
|                                       
|Investments in affiliates               |                                                  |                           | 14,177,866                 |               |             |             |          |             |           |            |            |             |      |   | 14,177,866  |            
|                                       
|                                       
|                                       
|                                       
|Deposits and other assets               |                                                  |                           | 5,473,280                  |               |             |             | 34,082    |             |           |            | (2,704,000 | )(j)        |      |   | 2,803,362   |            
|                                        |                                                  |                           |                            |               |             |             |           |             |           |            |            |             |      |   |             |            
|                                        |                                                  |                           | 242,703,221                |               |             |             | 4,830,425 |             |           |            |            |             |      |   | 258,891,782 |            
|                                        |                                                  |                           |                            |               |             |             |           |             |           |            |            |             |      |   |             |            
|Current liabilities:                    |                                                  |                           |                            |               |             |             |           |             |           |            |            |             |      |   |             |            
|                                       
|                                       
|                                       
|                                       
|                                        | Current maturities of long-term debt             |                           |                            | 30,059,696    |             |             |           | 741,306     |           |            |            |             |      |   |             | 30,801,002  |            
|                                       
|                                       
|                                       
|                                       
|                                        | Trade accounts payable                           |                           |                            | 14,956,324    |             |             |           | 1,223,017   |           |            |            |             |      |   |             | 16,179,341  |            
|                                       
|                                       
|                                       
|                                       
|                                        | Accrued expenses                                 |                           |                            | 15,380,136    |             |             |           | 991,495     |           |            |            |             |      |   |             | 16,371,631  |            
|                                       
|                                       
|                                       
|                                       
|                                        | Customer deposits                                |                           |                            | 453,198       |             |             |           |            |           |            |            |             |      |   |             | 453,198     |            
|                                       
|                                       
|                                       
|                                       
|                                        | Deferred revenue                                 |                           |                            | 5,538,705     |             |             |           | 2,704,000   |           |            |            | (2,704,000  | )(j) |   |             | 5,538,705   |            
|                                        |                                                  |                           |                            |               |             |             |           |             |           |            |            |             |      |   |             |            
|                                        |                                                  | Total current liabilities |                            |               | 66,388,059  |             |           |             | 5,659,818 |            |            |             |      |   |             |             | 69,343,877  |            
|                                        |                                                  |                           |                            |               |             |             |           |             |           |            |            |             |      |   |             |            
|Long-term debt, less current maturities |                                                  |                           | 2,998                      |               |             |             | 335,743   |             |           |            |            |             |      |   | 338,741     |            
|                                       
|                                       
|                                       
|                                       
|Stockholders equity:                   |                                                  |                           |                            |               |             |             |           |             |           |            |            |             |      |   |             |            
|                                       
|                                       
|                                       
|                                       
|                                        | Other stockholders equity                       |                           |                            | 165,625,250   |             |             |           | 22,603,060  |           |            |            | (22,603,060 | )(d) |   |             | 184,892,250 |            
|                                        |                                                  |                           |                            |               |             |             |           |             |           |            | 2,471,000  | (h)         |      |   |             |            
|                                        |                                                  |                           |                            |               |             |             |           |             |           |            | 16,796,000 | (d)         |      |   |             |            
|                                       
|                                       
|                                       
|                                       
|                                        | Retained earnings (deficit)                      |                           |                            | 11,915,059    |             |             |           | (23,768,196 | )         |            |            | 23,768,196  | (d)  |   |             | 5,545,059   |            
|                                        |                                                  |                           |                            |               |             |             |           |             |           |            | (6,370,000 | )(g)        |      |   |             |            
|                                       
|                                       
|                                       
|                                       
|                                        | Cumulative translation adjustment                |                           |                            | (1,228,145    | )           |             |           |            |           |            |            |             |      |   |             | (1,228,145  | )          
|                                        |                                                  |                           |                            |               |             |             |           |             |           |            |            |             |      |   |             |            
|                                        |                                                  |                           | Total stockholders equity |               |             | 176,312,164 |           |             |           | (1,165,136 | )          |             |      |   |             |             |             | 189,209,164 | 
|                                        |                                                  |                           |                            |               |             |             |           |             |           |            |            |             |      |   |             |            
|                                        |                                                  | $                         | 242,703,221                |               |             | $           | 4,830,425 |             |           |            |            |             |      | $ | 258,891,782 |            
|                                        |                                                  |                           |                            |               |             |             |           |             |           |            |            |             |      |   |             |            

8



---



FSI International, Inc. and Subsidiaries

Notes To Unaudited Pro Forma


As of and for the fiscal year ended August 28, 1999

The unaudited pro forma condensed combined financial statements
give effect to the following pro forma adjustments relating to
the acquisition of YieldUP:



| |                                                                                                                                                                                                           
| | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | (a)  To reflect the excess of acquisition cost over the fair
	 value of net assets acquired. The purchase price, purchase-price
	 allocation, and financing of the transaction are summarized as
	follows:

|                                                                                        |                        |   |            |           |  |  |  |            | 
|--------------------------------------------------------------------------------------- | ---------------------- | - | ---------- | --------- |  |  |  | ---------- | 
|                                                                                       
|                                                                                       
|                                                                                       
|                                                                                       
|Purchase price paid:                                                                    |                        |   |            |          
|Cash                                                                                    |                        | $ | 6,083,000  |          
|Common stock                                                                            |                        |   | 16,796,000 |          
|Costs associated with transaction                                                       |                        |   | 630,000    |          
|Value of FSI options issued in substitution of YieldUPs options and impact of warrants |                        |   | 2,471,000  |          
|                                                                                        |                        |   |            |           |  |  |  |           
|Total purchase consideration                                                            |                        | $ | 25,980,000 |          
|                                                                                        |                        |   |            |           |  |  |  |           
|                                                                                       
|                                                                                       
|                                                                                       
|                                                                                       
|Allocated to:                                                                           |                        |   |            |          
|In-process research and development write-off                                           |                        | $ | 6,370,000  |          
|Historical book value of YieldUPs assets and liabilities as
	 of September 30, 1999    |                        | $ | (1,165,136 | )         |  |  |  |           
|                                                                                       
|                                                                                       
|                                                                                       
|                                                                                       
|Adjustments to step up assets and liabilities to fair value:                            |                        |   |            |           |  |  |  |           
|                                                                                        | Inventory              |   |            | 2,245,000 |  |  |  | 1,079,864  | 
|                                                                                        |                        |   |            |           |  |  |  |           
|Excess purchase price over allocation to identifiable assets and
	liabilities:          |                        |   |            |           |  |  |  |           
|                                                                                        | Developed technology   |   |            | 9,150,000 |  |  |  |            | 
|                                                                                        | Assembled workforce    |   |            | 760,000   |  |  |  |            | 
|                                                                                        | Patent portfolio       |   |            | 3,920,000 |  |  |  |            | 
|                                                                                        | Customer relations     |   |            | 260,000   |  |  |  |            | 
|                                                                                        | Non-compete agreements |   |            | 160,000   |  |  |  |            | 
|                                                                                        | Goodwill               |   |            | 4,280,136 |  |  |  | 18,530,136 | 
|                                                                                        |                        |   |            |           |  |  |  |           
|Total allocation                                                                        |                        | $ | 25,980,000 |          
|                                                                                        |                        |   |            |           |  |  |  |           



| |                                                                                                                                                                                                                                                                                                                                                                                                                       
| | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | FSI issued 1,303,386 shares of FSI stock to consummate the
	transaction based on the 0.1567 conversion ratio. FSI also issued
	 options covering 209,278 shares of its common stock in
	substitution for previously outstanding options to acquire
	YieldUPs common stock. For purposes of accounting for this
	transaction, the fair value of the stock was determined as the
	average of the closing price of FSIs

9



---



FSI International, Inc. and Subsidiaries


Notes To Unaudited Pro Forma  (Continued)




| |                                                                                                                        
| | -----------------------------------------------------------------------------------------------------------------------
| | common stock for the 5 days before, the 5 days after,
	and the date of the reorganization agreement, January 21,
	1999.



| |                                                              
| | -------------------------------------------------------------
| | The valuation of intangible assets was determined as follows:

Developed Technology



| |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
| | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | Developed product technology represents proprietary know-how that
	 is technologically feasible as of the valuation date of
	October 20, 1999. As of the valuation date, YieldUP had four
	 developed series of products, the Omega 1000, Omega 2000, Omega
	4000 and Omega 6000 systems. The developed technology was valued
	by discounting forecasted cash flow directly related to each
	existing product technology. This included cash flows resulting
	from both the sale of the current product and from an imputed
	royalty rate on the sale of next generation products that are
	expected to primarily leverage certain developed technologies,
	which were in-process as of the valuation date.                                                                                                                                                                                    
|
| | Returns of and on the estimated fair value of the tangible and
	intangible contributory assets were deducted from the cash flow
	model to arrive at an estimate of the cash flow generated by the
	technology being analyzed. These contributory assets include the
	fixed assets, assembled workforce and trademark assets previously
	 valued.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|
| | To assess the value of developed technology assets, discount
	rates were derived after considering the risks attributable to
	the projected cash flows of each technology product. The
	Omega 1000 and 2000 products were introduced in 1997 and
	their projected revenues are considered less risky than recently
	introduced products. The Company assigned a discount rate of
	15 percent to their forecast cash flows, giving
	consideration to the lower risk associated with these assets. The
	 Omega 4000 and 6000 products were recently introduced in 1998
	and do not have a well developed customer base. Subsequently, a
	higher discount rate of 16 percent was applied to each of
	their forecast cash flows. To assess the value of the core
	technology asset, a discount rate of 18 percent was applied
	to the forecast cash flows of the royalties to the core
	technology.

Assembled Workforce



| |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
| | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | As of the October 20, 1999 valuation date, YieldUP possessed
	 a skilled assembled workforce of 53 employees. YieldUPs
	workforce is highly skilled and a valuable asset from FSIs
	perspective. FSI valued the trained and assembled YieldUP
	workforce using the replacement cost approach. This approach
	determines the price a similar company would pay to replace the
	workforce on an after-tax basis. The result is equivalent to the
	premium a purchaser would pay for a company with an assembled
	workforce in place. FSI management estimated the costs associated
	 with creating an assembled workforce in this industry, as well
	as an overview of those employees deemed critical to the
	enterprise.

10



---



FSI International, Inc. and Subsidiaries


Notes To Unaudited Pro Forma  (Continued)


Patent Portfolio



| |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
| | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | YieldUP has received 12 United States patents relating to its
	products and technologies, and has filed 24 additional U.S. and
	foreign patent applications. The 12 U.S. patents received by
	YieldUP relate to methods and apparatus for delivering ultra-low
	particle counts in semiconductor manufacturing, methods for
	cleaning and drying a semiconductor wafer, and an ultra-low
	particle semiconductor cleaner. These patents were issued from
	1996 through 1999.                                                                   
|
| | On January 21, 1999, YieldUP and FSI signed a license
	agreement to allow FSI to use all patented and patent-pending
	technology in connection with FSIs semiconductor cleaning,
	rinsing, and drying products. In return, FSI would pay a royalty
	to YieldUP for the use of the patented technology.                                                                                                                                                                                                                                        
|
| | It was assumed that all existing and in-process technology
	products would be subject to the patent royalty throughout their
	product lives. As discussed, the value of a patent can be
	estimated using an income approach commonly referred to as a
	relief-from-royalty method. This approach estimates the future,
	after-tax royalties avoided by the subject companys
	ownership of the patented technology, and discounts them to a
	present value at an appropriate discount rate, thereby arriving
	at an estimate of its fair value.

Customer Relations



| |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
| | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | YieldUP possesses established customer relationships with several
	 large companies who had previously purchased YieldUPs
	cleaning, rinsing, and drying products. These relationships have
	value because some of these existing customers may choose to make
	 follow-up purchases for their wafer fabrication facilities to
	compliment their existing equipment. YieldUPs sales channel
	 has material value in the context of YieldUPs business
	model of selling evaluation versions of its products to gain
	customer acceptance and is viewed by FSI as a valuable asset. It
	was estimated that the absence of YieldUPs sales
	channel/customer relationships would be expected to negatively
	impact revenues through the end of 2002. The difference
	represents the incremental revenue that is attributable to having
	 the existing customer relationships in place.
|
| | From this incremental revenue forecast, variable expenses were
	deducted, as well as variable cash flow adjustments that would be
	 expected in the event of such a decline in revenues. Net cash
	flow was then discounted to a present value at an appropriate
	rate of return in order to estimate the fair value of
	YieldUPs sales channel.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|
| | Customer relationships were also valued using the
	replacement-cost approach. This approach determines the price a
	similar company would pay to develop the customer relationships
	on an after-tax basis. The result is equivalent to the premium a
	purchaser would pay for a company with customer relationships in
	place.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       

11



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FSI International, Inc. and Subsidiaries


Notes To Unaudited Pro Forma  (Continued)


Non-Compete Agreements



| |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
| | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | Under the reorganization agreement, three key YieldUP employees
	signed employment agreements with the surviving corporation in
	the merger. Since these employment agreements are on an at
	will basis, with no penalties to the employee for leaving
	his employment, no value was separately assigned to these
	employment agreements. Within these three employment agreements
	are non-compete agreements that preclude these individuals from
	competing with FSI for a period of two years following
	termination of their employment.
|
| | It was estimated that potential competition from the three key
	employees would be expected to negatively impact revenues through
	 the end of 2001. The difference represents the incremental
	revenue that is attributable to having the non-competition
	agreements in place.                                                                                                                                                                                                                                                               
|
| | From this incremental revenue forecast, variable expenses were
	deducted, as well as variable cash flow adjustments that would be
	 expected in the event of such a decline in revenues. Net cash
	flow was then discounted to a present value at an appropriate
	rate of return in order to estimate the fair value of the
	non-competition agreements.                                                                                                                                                                                       



| |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
| | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | (b)  To reflect the step-up in inventory values to fair
	value based on estimated selling prices of finished goods and
	demonstration inventory.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|
| | (c)  To reflect the cash portion of the purchase price
	including cash paid to YieldUP stockholders and FSIs costs
	associated with the merger.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|
| | (d)  To reflect the elimination of the stockholders
	equity accounts of YieldUP and to reflect the issuance of FSI
	common stock as partial consideration for the merger.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|
| | (e)  Represents the amortization of goodwill and other
	intangibles related to the acquisition of YieldUP over periods
	ranging from two to nine years, reflecting an estimate of the
	useful life of the intangibles.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|
| | (f)  Represents the reduction in interest income earned by
	FSI for the fiscal year ended August 28, 1999 on cash in the
	 amount of the consideration paid for the acquisition of YieldUP
	that would not have been earned had the acquisition been
	consummated as of the beginning of the period.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|
| | (g)  As part of the merger, FSI will be acquiring projects
	under development, including the YieldUP 8000 series. The YieldUP
	 8000 series is based on a technology that integrates multiple
	gas-based cleaning technologies, while also providing for the use
	 of existing liquid based technologies. In addition, the YieldUP
	8000 is being designed from the ground up as a modular,
	multi-tank-cleaning solution designed to replace conventional wet
	 benches. The YieldUP 8000 series will debut with the YieldUP
	8300, a three-tank system. The 8300 is designed to be modifiable,
	 with the addition or removal of cleaning tank modules, to form
	other models including the 8100 (1 tank), 8200
	(2 tanks), and 8400 (4 tanks). These other models in
	the 8000 series will be introduced over time, based on market
	demand and product mix.

12



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FSI International, Inc. and Subsidiaries


Notes To Unaudited Pro Forma  (Continued)




| |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
| | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | The 8000 series is designed to integrate multiple gas-based
	cleaning technologies including ammonia, HF, and/or HCI, as well
	as traditional liquid-based cleaning technologies. Semiconductor
	manufacturers can customize their cleaning process with their
	choice of various chemicals in their gaseous or liquid forms in
	order to provide a total cleaning solution that works best for
	their specific substrate. One advantage of gas-based cleaning is
	that it requires very dilute chemistries to be effective, where
	concentrations of parts per billion are sufficient. Dilute
	chemical concentrations result in a lower cost of ownership for
	the customers and reduce environmental contamination by these
	hazardous chemicals. Another advantage is that gas is inherently
	less subject to particles and other impurities than liquids and
	therefore cleaning will cause less wafer contamination. This
	makes it essential for use in new smaller geometries of
	0.25 micron and below.
|
| | The modularity of the 8000 series will allow the product to be
	placed in various compact configurations within a cleanroom. The
	use of tanks for multiple purposes, that is cleaning, rinsing,
	and drying, makes it possible to achieve much smaller footprints
	than conventional wet benches. The compact and modular nature of
	the product will also lower the cost of ownership by reducing the
	 required amount of cleanroom space, which can cost thousands of
	dollars per square meter.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
|
| | The 8000 series also enables the use of new and revolutionary
	ammonia and IPA charging drying technologies. This gas-based
	drying technology carries many of the advantages of gas-based
	cleaning, including reduced wafer contamination, reduced
	environmental contamination, and the use of very dilute
	chemistries, resulting in a lower cost of ownership. This
	revolutionary drying technology also makes it possible to
	effectively rinse and dry very large substrates in short periods
	of time, increasing wafer throughput.                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
|
| | YieldUP initiated development of the 8000 series in the fourth
	quarter of 1997. YieldUP has spent approximately
	3.3 man-years of effort to date in the development of the
	8000 series. YieldUP believes that it requires an additional
	1.8 man-years of effort to get the 8000 series to
	technological feasibility. YieldUPs 8300 is expected to
	reach a beta version at the beginning of the first quarter of
	fiscal 2001, at which point the product will be sold as an
	evaluation version to be modified as necessary. The Company
	expects to spend another $2.9 million by the end of fourth
	quarter 2000 to complete the technology.                                                                                                                                                                                                                                                                                                                                                            
|
| | In-process research and development was valued by discounting
	forecasted cash flow directly related to the products expecting
	to result from the subject research and development. In each
	instance where a developed, core technology is expected to be
	leveraged, a charge for core technology was deducted from the
	forecast to provide a fair return on the leveraged technology.
	The assumed charge for core technology is 2% of revenues on an
	after-tax basis.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
|
| | The charge for core technology is deducted from the in-process
	product forecasts in addition to the royalty rate for patented
	and patent-pending technology. The basis for the charge for core
	technology is to provide a fair return on any                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 

13



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FSI International, Inc. and Subsidiaries


Notes To Unaudited Pro Forma  (Continued)




| |                                                                                                                
| | ---------------------------------------------------------------------------------------------------------------
| | leveraged, but non-patentable technology, including trade
	secrets, know-how, and other proprietary technology.



| |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
| | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | Returns of and on the estimated fair value of the tangible and
	intangible contributory assets were deducted from the cash flow
	model to arrive at an estimate of the cash flow generated by the
	technology being analyzed. These contributory assets include the
	assembled workforce and trademark assets previously valued.                                                                                                                                                                                                                                                                                                                                                                                            
|
| | To estimate the fair value of the in-process research and
	development assets, a discount rate of 26.5% was employed,
	developed by analyzing the project and market risks associated
	with the research and development effort, both in terms of costs
	invested as of the valuation date relative to completion costs
	and technical achievements. This discount rate represents a
	significant premium above the discount rate utilized in the
	valuation of existing product technology to account for the
	additional risks associated with in-process product technologies.                                                                                                                                           
|
| | FSI developed a calculation of the value of in-process research
	and development assets that excludes cash flows attributable to
	remaining development efforts required to develop the acquired
	incomplete technology into commercially viable products. The
	calculation of excluded cash flow was determined by evaluating
	the costs, development time, and technological complexity
	required to develop the in-process technology into commercially
	viable products. Based upon FSI managements estimate that
	the in-process technology is 65% complete, it is their opinion
	that the value of the in-process research and development assets
	as of the valuation date is reasonably estimated at
	$6.4 million.
|
| | The 8000 series represents a high-risk in-process technology
	asset since the 8000 series is based on an entirely new platform
	than YieldUPs current products. Certain technology
	developed by YieldUP for the 8000 series is revolutionary as the
	8000 series represents YieldUPs first product to integrate
	both multiple gas-based cleaning technologies and gas-based
	drying technology within a modular configuration design with a
	low cost of ownership. Some of this technical risk is moderated
	by the projects late stage of development.                                                                                                                                                               
|
| | Market research indicates that there will be significant demand
	for a fully integrated wafer cleaning solution, such as the 8000
	series. However, YieldUP is a new entrant in the wet bench market
	 and may face significant competition from more established
	players.                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|
| | Therefore, an unusual charge of $6.4 million should be
	reflected in the income statement of FSI in the reporting period
	in which the consummation of the merger occurs due to the
	immediate write-off of in-process research and development. At
	the effective date, the technological feasibility of the acquired
	 technology has not been established and the technology has no
	alternative uses.                                                                                                                                                                                                                                                                                                                   

14



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FSI International, Inc. and Subsidiaries


Notes To Unaudited Pro Forma  (Continued)




| |                                                                                                                                                                                                                                                                                                                                                             
| | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | (h)  To record the value of the FSI options issued in
	substitution of YieldUP options and the impact of warrants as
	part of the purchase price. The fair value of the stock options
	and the impact of the warrants was determined at the acquisition
	date using the Black-Scholes option-pricing model with the
	following weighted average assumptions:

|                                  |  |  |               |  
|--------------------------------- |  |  | ------------- | -
|Expected dividend yield           |  |  | 0.0%          |  
|Annualized stock price volatility |  |  | 58.9%         |  
|Risk free interest rate           |  |  | 5.1%          |  
|Expected life (years)             |  |  | 5.5 (options) |  
|Expected life (years)             |  |  | 1.8 (warrants | )



| |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
| | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | The Black-Scholes option valuation model represents only an
	estimate of the fair value of FSIs options because the
	model was developed for use in estimating the fair value of
	traded options that, unlike FSIs options, have no vesting
	restrictions and are fully transferable. In addition, the
	Black-Scholes model requires the input of highly subjective
	assumptions including the annualized stock price volatility.                                                                                                                                                                                                                                                                                                                                                       
|
| | (i)  Basic pro forma net income per common share was
	computed by dividing pro forma net income by the pro forma
	combined weighted average number of shares of common stock
	outstanding during the period. Diluted pro forma net income per
	common share was calculated using the treasury stock method to
	compute the weighted average common stock outstanding assuming
	the conversion of dilutive potential common shares. The effect of
	 stock options was not included in the calculation of dilutive
	income per share because their inclusion would have been
	anti-dilutive. The pro forma adjustment for combined weighted
	average number of common shares was based upon the number of
	common shares of YieldUP outstanding multiplied by the exchange
	ratio of 0.1567.
|
| | (j)  To eliminate FSIs license fee asset and
	YieldUPs deferred revenue related to a pre-paid license fee
	 paid by FSI to YieldUP.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     

15